Base station apparatus and communication control method

ABSTRACT

A base station apparatus capable of communicating with a user equipment terminal using an uplink shared channel includes a radio resource allocation unit configured to decrease frequency resources allocated to the shared channel, when transmission power of the user equipment terminal is less than a predetermined threshold.

TECHNICAL FIELD

The present invention generally relates to a mobile communication systememploying an Orthogonal Frequency Division Multiplexing (OFDM) scheme,and more particularly to a base station apparatus and a communicationcontrol method.

BACKGROUND ART

As a next-generation system of the W-CDMA (Wideband Code DivisionMultiple Access) and the HSDPA (High Speed Downlink Packet Access), anLTE system has been studied by 3GPP (3^(rd) Generation PartnershipProject) which is a standards body of the W-CDMA. In the LTE system as aradio access system, an OFDM (Orthogonal Frequency DivisionMultiplexing) scheme and an SC-FDMA (Single-Carrier Frequency DivisionMultiple Access) scheme have been studied to be applied to the downlinkcommunication system and the uplink communication system, respectively(see, 3GPP TR 25.814 (V7.0.0), “Physical Layer Aspects for EvolvedUTRA”, June 2006, for example).

In the OFDM scheme, a frequency band is divided into plural sub-carriershaving narrower frequency bands, and data are transmitted on each subfrequency band (sub-carrier) and the sub-carriers are closely arrangedso as not to interfere with each other, so that fast data transmissioncan be achieved and an efficiency use of the frequency band can beimproved.

In the SC-FDMA scheme, a frequency band is divided in a manner so thatdifferent frequencies can be separately used among plural terminals(user equipment terminals) and as a result, interference betweenterminals can be reduced. Further, in the SC-FDMA scheme, a range oftransmission power fluctuation can be made smaller; therefore lowerenergy consumption of terminals can be achieved and a wider coveragearea can be obtained.

The LTE system is a communication system using shared channels in bothdownlink and uplink. For example, in uplink, a base station apparatusselects a user equipment terminal to communicate using the sharedchannel in each sub-frame (each 1 ms) and instructs, using the downlinkcontrol channel, the selected user equipment terminal to communicateusing the shared channel in a predetermined sub-frame. The userequipment terminal transmits the shared channel based on the downlinkcontrol channel. The base station apparatus receives and decodes theshared channel transmitted from the user equipment terminal. In thiscase, a process of selecting the user equipment terminal to communicateusing the shared channel as described above is called a schedulingprocess.

Further, in the LTE system, so-called Adaptive Modulation and Coding(AMC) is applied; therefore, transmission formats of the shared channelsmay vary among different sub-frames. As used herein, the transmissionformat includes various information items indicating such as allocationinformation about resource blocks (frequency resources), a modulationscheme, a payload size, information about transmission power, HARQ(Hybrid Automatic Repeat reQuest) information (a Redundancy versionparameter, a process number, etc.), and MIMO (Multiple Input MultipleOutput) information (a reference signal sequence for MIMO transmission,etc.). The transmission format of the shared channel and identificationinformation of the user equipment terminal which communicates using theshared channel in the corresponding sub-frame are collectively called anUplink Scheduling Grant.

In the LTE system, the transmission format of the shared channel andidentification information of the user equipment terminal whichcommunicates using the shared channel in the corresponding sub-frame arereported using a Physical Downlink Control Channel (PDCCH). The PhysicalDownlink Control Channel (PDCCH) may also be called a DL L1/L2 ControlChannel.

DISCLOSURE OF INVENTION Problem(s) to be Solved by the Invention

When the scheduling process or a process of determining the transmissionformat in the AMC (Adaptive Modulation and Coding) scheme is notadequately controlled, the transmission characteristics or radiocapacity of the system may be impaired.

The present invention is made in light of the problems and may provide abase station apparatus and a communication control method capable of, inLTE uplink, adequately performing the scheduling process and thedetermination process of the transmission formats in the AMC scheme.

Means for Solving the Problem(s)

In one aspect of the present invention, there is provided a base stationapparatus capable of communicating with a user equipment terminal usingan uplink shared channel, including:

a radio resource allocation unit configured to decrease frequencyresources allocated to the shared channel, when transmission power ofthe user equipment terminal is less than a predetermined threshold.

In another aspect of the present invention, there is provided a basestation apparatus capable of communicating with a user equipmentterminal using an uplink shared channel, including:

a storage unit configured to store a correspondence between a radioresource available for the shared channel, uplink radio qualityinformation, and a transmission scheme used for transmitting the sharedchannel;

a determination unit configured to determine the transmission scheme tobe used for transmitting the shared channel based on the uplink radioquality information and the radio resource available for the sharedchannel with reference to the storage unit; and

a notification unit configured to notify the user equipment terminal ofthe determined transmission scheme.

In another aspect of the present invention, there is provided a basestation apparatus capable of communicating with a user equipmentterminal using an uplink shared channel, including:

a calculation unit configured to calculate path loss between the userequipment terminal and the base station apparatus;

an MCS selection unit configured to select an MCS level of the sharedchannel based on the path loss;

a determination unit configured to determine a transmission scheme to beused for transmitting the shared channel based on the MCS level and aradio resource available for the shared channel; and

a notification unit configured to notify the user equipment terminal ofthe determined transmission scheme.

In another aspect of the present invention, there is provided acommunication control method in a base station apparatus capable ofcommunicating with a user equipment terminal using an uplink sharedchannel, including the steps of:

calculating path loss between the user equipment terminal and the basestation apparatus;

selecting an MCS level of the shared channel based on the path loss,radio quality of a sounding reference signal, and target radio qualityof the sounding reference signal;

determining a transmission scheme to be used for transmitting the sharedchannel based on the MCS level and a radio resource available for theshared channel; and

notifying the user equipment terminal of the determined transmissionscheme.

ADVANTAGEOUS EFFECT OF THE INVENTION

According to an embodiment of the present invention, there may beprovided a base station apparatus and a communication control methodcapable of, in LTE uplink, adequately performing the scheduling processand the determination process of the transmission formats in the AMC.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram showing a configuration of a radiocommunication system according to an embodiment of the presentinvention.

FIG. 2 is a flowchart showing a process of UL MAC data transmissionaccording to an embodiment of the present invention.

FIG. 3 is a flowchart showing a process of scheduling coefficientcalculation and candidate UE selection according to an embodiment of thepresent invention.

FIG. 4 is a flowchart showing a process of control for a TFR selectionaccording to an embodiment of the present invention.

FIG. 5 shows an UL_TF_Related_Table.

FIG. 6 is a partial block diagram of a base station apparatus accordingto an embodiment of the present invention.

FIG. 7A is a flowchart showing a transmission process of an ULScheduling Grant and a PHICH according to an embodiment of the presentinvention.

FIG. 7B is a flowchart showing a process of scheduling coefficientcalculation and candidate UE selection according to an embodiment of thepresent invention.

FIG. 8 is a flowchart of a process of UL TFR selection.

FIG. 9 is a schematic diagram showing an effect of reserving persistentresources when radio resources are to be allocated according to dynamicscheduling to a user equipment terminal (UE) to which the persistentresources are allocated.

FIG. 10 is a schematic diagram showing an effect of reserving persistentresources when radio resources are to be allocated according to dynamicscheduling to a user equipment terminal (UE) to which the persistentresources are allocated.

FIG. 11A is a flowchart of a process of UL TFR selection.

FIG. 11B is another flowchart of a process of UL TFR selection.

FIG. 11C shows an example of a relationship between path loss (Pathloss)and P_(OFFSET).

FIG. 12A shows an example of a TF_Related_table.

FIG. 12B shows an example of a TF_Related_table.

FIG. 13A is a schematic diagram showing interference in a user equipmentterminal.

FIG. 13B is a schematic diagram showing interference of an uplinktransmission signal with a downlink reception signal.

FIG. 14 is a flowchart of a process of determining a Temporary RB group.

FIG. 15 shows an example of a relationship between path loss (Pathloss)and MCS.

FIG. 16 is a partial block diagram of a base station apparatus accordingto an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Description ofNotations

-   -   50 cell    -   100 ₁, 100 ₂, 100 ₃, 100 _(n) user equipment terminal    -   200 base station apparatus    -   206 scheduling coefficient calculation unit    -   210 transport format and resource block selection unit    -   212 layer 1 processing unit    -   300 access gateway apparatus    -   400 core network

BEST MODE OF CARRYING OUT THE INVENTION First Embodiment

Next, a best mode for carrying out the present invention is describedbased on a first embodiment described below with reference to theaccompanying drawings.

Throughout the figures for illustrating the embodiments of the presentinvention, the same reference numerals are used for the same orequivalent elements and their repeated descriptions may be omitted.

First, a radio communication system having a base station apparatusaccording to an embodiment of the present invention is described withreference to FIG. 1.

As shown in FIG. 1, the radio communication system 1000, which may be anEvolved UTRA (Universal Terrestrial Radio Access) and UTRAN (UTRANetwork) system (a.k.a an LTE (Long Term Evolution) system or a super 3Gsystem), includes a base station apparatus (eNB: eNode B) 200 and pluralsets of user equipment (UE) 100 _(n) (100 ₁, 100 ₂, 100 ₃, . . . 100_(n); an integer greater than zero (0)) (hereinafter, the user equipment(UE) may be referred to as a user equipment terminal(s)). The basestation apparatus 200 is connected to an upper node such as an accessgateway apparatus 300. The access gateway apparatus 300 is connected toa core network 400. In this case, the user equipment terminals 100 _(n)are in communication with the base station apparatus 200 in a cell 50based on the Evolved UTRA and UTRAN radio communication scheme.

Each of the user equipment terminals (100 ₁, 100 ₂, 100 ₃, . . . 100_(n)) has the same configuration, functions, and status. Therefore,unless otherwise described, the term of user equipment terminals (UE)100 _(n) may be collectively used in the following descriptions.

As the radio access scheme in the radio communication system 1000, theOFDM (Orthogonal Frequency Division Multiplexing) scheme and the SC-FDMA(Single-Carrier Frequency Division Multiplexing Access) scheme are usedin downlink and uplink communications, respectively. As described above,the OFDM scheme is a multi-carrier transmission scheme in which afrequency band is divided into plural sub-carriers having narrowfrequency bands and data are mapped on each sub-carrier to betransmitted. The SC-FDMA scheme is a single-carrier transmission schemein which a frequency band is divided so that different frequencies canbe used among plural terminals and as a result, interference betweenterminals can be reduced.

Next, communication channels used in the Evolved UTRA and UTRAN radiocommunication scheme are described.

In downlink communications, a Physical Downlink Shared Channel (PDSCH)that is shared among the user equipment terminals 100 _(n) and aPhysical Downlink Control Channel (PDCCH) are used. The PhysicalDownlink Control Channel (PDCCH) may also be called a DL L1/L2 ControlChannel. In downlink, transport format information and user informationof the user to which the Physical Downlink Shared Channel istransmitted, transport format information and user information of theuser by which a Physical Uplink Shared Channel (PUSCH) is transmitted,acknowledge information of the PUSCH (or an Uplink Shared Channel(UL-SCH) as a transport channel), and the like are reported via thePhysical Downlink Control Channel (PDCCH). User data are transmitted viathe Physical Downlink Shared Channel. The user data are transmitted viaa Downlink Shared Channel (DL-SCH) as a transport channel.

In uplink communication, the Physical Uplink Shared Channel (PUSCH) thatis shared among user equipment terminals 100 _(n) and an LTE controlchannel are used. The LTE control channel has two types; one is to betime-multiplexed with the Physical Uplink Shared Channel (PUSCH) and theother is to be frequency-multiplexed with the Physical Uplink SharedChannel (PUSCH). The control channel to be frequency-multiplexed withthe Physical Uplink Shared Channel (PUSCH) is called a Physical UplinkControl Channel (PUCCH).

In uplink communication, a downlink Channel Quality Indicator (CQI) tobe used for scheduling for the Downlink Shared Channel (DL-SCH) andAdaptive Modulation and Coding (AMC), and acknowledgement information ofthe Downlink Shared Channel (HARQ ACK information) are transmitted viathe LTE control channel. Further, user data are transmitted via thePhysical Uplink Shared Channel (PUSCH). The user data are transmittedvia an Uplink Shared Channel (UL-SCH) as a transport channel.

1. Uplink MAC Communication Control Procedure

Next, an uplink MAC (UL MAC) communication control procedure as acommunication control method performed in a base station apparatusaccording the present embodiment is described.

In this embodiment, a logical channel corresponds to, for example, aRadio bearer; and a priority class corresponds to, for example, apriority level (or priority).

Unless otherwise described, the “corresponding sub-frame” refers to asub-frame in which the user equipment terminal transmits the UplinkShared Channel (UL-SCH) according to scheduling.

In the following descriptions, dynamic scheduling corresponds to a firstresource allocating scheme for dynamically allocating radio resources.When dynamic scheduling is applied to the Uplink Shared Channel(UL-SCH), radio resources are allocated to the user equipment terminalin arbitrary sub-frames. Further, in this case, various values may beset as the values of the transmission format including allocationinformation about resource blocks (frequency resources), a modulationscheme, a payload size, information about transmission power, HARQinformation (a Redundancy version parameter, a process number, etc.),and MIMO information (a reference signal sequence for MIMO transmission,etc.).

On the other hand, persistent scheduling is a scheduling scheme forperiodically allocating data transmission opportunities in accordancewith a data type or features of the application to transmit/receivedata. Persistent scheduling corresponds to a second resource allocatingscheme for periodically allocating radio resources. Namely, whenpersistent scheduling is applied to the Uplink Shared Channel (UL-SCH),radio resources are allocated to the user equipment terminal inpredetermined sub-frames. Further, in this case, predetermined valuesare set as the values of the transmission format including allocationinformation about resource blocks (frequency resources), a modulationscheme, a payload size, information about transmission power, HARQinformation (a Redundancy version parameter, a process number, etc.),and MIMO information (a reference signal sequence for MIMO transmission,etc.). Namely, radio resources are allocated in the predeterminedsub-frames, and the Uplink Shared Channel (UL-SCH) is transmitted usingthe predetermined transmission format. In this case, the predeterminedsub-frames may be arranged, for example, at a predetermined cycle.Further, the predetermined transmission format is not necessarily fixedto one type, so that plural types of transmission formats may beprovided.

2. Allocation Unit of the Transmission Band for The Physical UplinkShared Channel (PUSCH)

In the present embodiment, the transmission band in the frequencydirection is allocated in terms of resource blocks (RBs). For example,one resource block (1 RB) corresponds to 180 kHz. The number of RBs isequal to 25 for the system bandwidth of 5 MHz, is equal to 50 for thesystem bandwidth of 10 MHz, and is equal to 100 for the system bandwidthof 20 MHz. Also, the transmission band for the PUSCH is allocated interms of RBs in each sub-frame. In addition, RBs are allocated such thatfactors of the DFT size do not include values other than 2, 3, and 5. Inother words, the factors of the DFT size only include 2, 3, and 5.

For retransmission of the Uplink Shared Channel (UL-SCH), the basestation apparatus 200 may or may not transmit the corresponding UplinkScheduling Grant. When the base station apparatus 200 transmits theUplink Scheduling Grant for retransmission of the Uplink Shared Channel(UL-SCH), the user equipment terminal retransmits the Uplink SharedChannel (UL-SCH) according to the Uplink Scheduling Grant. As describedabove, the Uplink Scheduling Grant includes the identificationinformation of the user equipment terminal which communicates using theshared channel in the corresponding sub-frame and also includes thetransmission format of the shared channel such as allocation informationabout resource blocks (frequency resources), a modulation scheme, apayload size, information about transmission power, HARQ information (aRedundancy version parameter, a process number, etc.), and MIMOinformation (a reference signal sequence for MIMO transmission, etc.).It should be noted that only a portion of the Uplink Scheduling Grantmay be modified from the corresponding portion for initial transmission.For example, only allocation information about resource blocks(frequency resources) and information about transmission power may bemodified. On the other hand, when the base station apparatus 200 doesnot transmit the Uplink Scheduling Grant for retransmission of theUplink Shared Channel (UL-SCH), the user equipment terminal retransmitsthe Uplink Shared Channel (UL-SCH) according to either the UplinkScheduling Grant for initial transmission or the previously receivedUplink Scheduling Grant for the Uplink Shared Channel (UL-SCH). Thisretransmission is performed for the PUSCH (the UL-SCH as the transportchannel) to which dynamic scheduling is applied. Alternatively, thisretransmission may be performed for the PUSCH (the UL-SCH as thetransport channel) to which persistent scheduling is applied. Inaddition, in the case of a Message-3 in the random access procedure, thebase station apparatus 200 may never transmit the Uplink SchedulingGrant for retransmission of the Uplink Shared Channel (UL-SCH).

As used herein, dynamic scheduling corresponds to a first resourceallocating scheme for dynamically allocating radio resources.

3. UL MAC Data Transmission Procedure

Next, an uplink MAC (UL MAC) data transmission procedure is describedwith reference to FIG. 2. FIG. 2 shows a procedure, starting from ascheduling process of calculating scheduling coefficients, to an UL TFRselection process of determining the transport format and RBs to beallocated.

3.1. Setting of UL MAC Maximum Multiplexing Number N_(ULMAX)

In step S202, an UL MAC maximum multiplexing number N_(ULMAX) is set inthe base station apparatus 200. The UL MAC maximum multiplexing numberN_(ULMAX) is the maximum multiplexing number in one sub-frame of theUplink Shared Channel (UL-SCH) (including both the UL-SCH for initialtransmission and the UL-SCH for retransmission) to which dynamicscheduling is applied and is designated via the external input interface(I/F).

3.2. Calculation for Scheduling Coefficients

Next, in step S204, Calculation for Scheduling coefficients is performedin the base station apparatus 200. The user equipment terminals (UEs) towhich radio resources are to be allocated according to dynamicscheduling in the corresponding sub-frame are selected. Then, UplinkTransport format and Resource selection is performed, as describedbelow, with respect to the user equipment terminals (UEs) to which radioresources are to be allocated according to dynamic scheduling in thecorresponding sub-frame.

The number of user equipment terminals (UEs) to which radio resourcesare to be allocated according to dynamic scheduling in the correspondingsub-frame is defined as N_(UL-SCH).

3.4. Uplink Transport Format and Resource Selection (UL TFR Selection)

Next, in step S208, Uplink Transport format and Resource selection isperformed in the base station apparatus 200. The base station apparatus200 reserves radio resources (RBs) for the Physical Random AccessChannel (PRACH), reserves prohibited radio resources (RBs) or guard RBs,reserves radio resources (RBs) for the UL-SCH to which persistentscheduling is applied, and then determines a transmission format for theUL-SCH to which dynamic scheduling is applied and allocates radioresources for the UL-SCH to which dynamic scheduling is applied(including for both initial transmission and retransmission).

4. Calculation for Scheduling Coefficients

Next, Calculation for Scheduling coefficients performed in step S204 isdescribed with reference to FIG. 3.

4.1. Process Flow

FIG. 3 shows a process of selecting candidates for the user equipmentterminals (UEs) to which radio resources are to be allocated accordingto dynamic scheduling, by calculating the scheduling coefficients. Thebase station apparatus 200 performs the following processes with respectto all the user equipment terminals (UEs) in an LTE active state (in anRRC (Radio Resource Control) connected state).

As shown in FIG. 3, in step S302, equations of n=1, N_(Scheduling)=0,N_(Retransmission)=0 are provided; where n denotes an index of the userequipment terminals 100 _(n) and n=1, . . . , N (N is an integer greaterthan 0).

4.1.1. Renewal of HARQ Entity Status

Next, in step S304, Renewal of HARQ (Hybrid Automatic Repeat reQuest)Entity Status is performed. In this step, with respect to the userequipment terminal (UE), a process in which the CRC result of the UL-SCHis OK is released.

Further, a process in which the maximum number of retransmission timeshas been reached is also released and the user data in the process arediscarded. As used herein, the maximum number of retransmission times is“the largest value selected from the maximum numbers of retransmissiontimes of all the logical channels which may be used by the userequipment terminal (UE) for transmission”.

The user equipment terminal (UE) performs HARQ based on the maximumnumber of retransmission times of the logical channel with the highestpriority class among logical channels to be multiplexed in the MAC PDU.For example, when the user equipment terminal uses the shared channel totransmit the transport channel including two or more logical channels,the user equipment terminal determines that the maximum number ofretransmission times of the transport channel is the maximum number ofretransmission times of the logical channel with the highest prioritylevel among the two or more logical channels.

Further, a process in which no transmission of the UL-SCH is detectedupon power detection of the Uplink Shared Channel is also released.

4.1.2. HARQ Retransmission Check

Next, in step S306, HARQ Retransmission Check is performed. It isdetermined whether the user equipment terminal (UE) has data to beretransmitted in the corresponding sub-frame. The “data to beretransmitted” refer to retransmission data which satisfy the followingfour conditions:

-   -   the timing of retransmitting data corresponds to the        retransmission timing according to Synchronous HARQ;    -   the previous CRC results of the UL-SCH are not OK;    -   the maximum number of retransmission times has not been reached;        and    -   “no transmission of the UL-SCH” is not detected upon power        detection of the Uplink Shared Channel.

When the user equipment terminal (UE) has data to be retransmitted, theprocess of the HARQ Retransmission Check returns “Retransmission”.Otherwise, the process of the HARQ Retransmission Check returns “Noretransmission”. When the result of the HARQ Retransmission Check isdetermined as “No retransmission”, the process goes to step S310 inwhich Measurement Gap Check is performed.

Since the maximum number of retransmission times of the UL-SCH isdetermined for each priority class of the logical channel, the basestation apparatus (eNB) performs the process assuming that the maximumnumber of retransmission times is the largest value selected from themaximum numbers of retransmission times of all the logical channelswhich may be used for transmission.

When the result of the HARQ Retransmission Check is determined as“Retransmission”, N_(Retransmission) is incremented by one in step S308(N_(Retransmission)++), and then the user equipment terminal (UE) isexcluded from a target of the scheduling process for initialtransmission. In addition, when persistent resources are allocated inthe corresponding sub-frame to the user equipment terminal's logicalchannel to which persistent scheduling is applied, the persistentresources are released. The RBs corresponding to the persistentresources are used for UL TFR Selection for the UL-SCH to which dynamicscheduling is applied.

As a result, retransmission according to dynamic scheduling hasprecedence over initial transmission according to persistent scheduling.

4.1.3. Measurement Gap Check

Next, in step S310, Measurement Gap Check is performed. In this step,the base station apparatus 200 does not allocate the Uplink SharedChannel (RBs for the Uplink Shared Channel) to the user equipmentterminal (UE), when the time interval during which the user equipmentterminal (UE) measures a cell with a different frequency overlaps a timeframe in which the Physical Downlink Control Channel for the UplinkShared Channel is transmitted in downlink, a time frame in which theshared channel is received, or a time frame in which acknowledgeinformation for the Uplink Shared Channel is transmitted. The ULScheduling Grant for the Uplink Shared Channel is transmitted via thePhysical Downlink Control Channel.

In this case, the cell with the different frequency may be a cell of theEvolved UTRA and UTRAN system or a cell of another system such as GSM,WCDMA, TDD-CDMA, CDMA-2000, or WiMAX.

Specifically, it is determined whether the sub-frame in which thePhysical Downlink Control Channel is transmitted is included in theMeasurement gap, whether the sub-frame in which the UL-SCH istransmitted is included in the Measurement gap, or whether the sub-framein which an ACK/NACK for the UL-SCH is transmitted is included in theMeasurement gap, with respect to initial transmission and secondtransmission from the user equipment terminal (UE). When it isdetermined that the sub-frame in which the Physical Downlink ControlChannel is transmitted is included in the Measurement gap, that thesub-frame in which the UL-SCH is transmitted is included in theMeasurement gap, or that the sub-frame in which the ACK/NACK for theUL-SCH is transmitted is included in the Measurement gap, the process ofthe Measurement Gap Check returns NG (failed). Otherwise, the process ofthe Measurement Gap Check returns OK. The Measurement gap refers to atime interval during which the user equipment terminal (UE) measures acell with a different frequency for the purpose of different-frequencyhandover or different-system handover. During the time interval,communications cannot be performed and therefore, the user equipmentterminal (UE) cannot receive the Physical Downlink Control Channel. Forthe same reason, the user equipment terminal (UE) cannot transmit theUplink Shared Channel and cannot receive the ACK/NACK. When the resultof the Measurement Gap Check is determined as NG, the user equipment(UE) terminal is excluded from a target of the scheduling process.

In this example, the Measurement Gap Check is not performed for thirdtransmission or later. Although the Measurement Gap Check is performedfor the initial transmission and second transmission in this example, itmay be performed for the initial transmission, second transmission, andthird transmission.

4.1.4. DRX Check

Next, in step S312, DRX (discontinuous reception) Check is performed.When the user equipment terminal (UE) performs DRX, that is, when theuser equipment terminal (UE) is in a DRX mode, the Uplink Shared Channel(RBs for the Uplink Shared Channel) is not allocated to the userequipment terminal (UE).

Specifically, it is determined whether the user equipment terminal (UE)is in the DRX mode. When it is determined that the user equipmentterminal (UE) is in the DRX mode, the process of the DRX Check returnsNG (failed). Otherwise, the process of the DRX Check returns OK. Whenthe result of the DRX Check is determined as NG, the user equipmentterminal (UE) is excluded from a target of the scheduling process forinitial transmission.

4.1.5. UL Sync Check

Next, in step S314, Uplink Synchronization Check (UL Sync Check) isperformed. In this step, when the user equipment terminal (UE) is out ofsynchronization, the Uplink Shared Channel (RBs for the Uplink SharedChannel) is not allocated to the user equipment terminal (UE).

Specifically, it is determined whether the uplink synchronization stateof the user equipment terminal (UE) is “Synchronization established”,“Out of Synchronization: Type A”, or “Out of Synchronization: Type B”.When it is determined that the uplink synchronization state is “Out ofSynchronization: Type A” or “Out of Synchronization: Type B”, theprocess of the UL Sync Check returns NG (failed). When it is determinedthat the uplink synchronization state is “Synchronization established”,the process of the UL Sync Check returns OK. When the result of the ULSync Check is determined as NG, the user equipment terminal (UE) isexcluded from a target of the scheduling process.

The base station apparatus (eNB) 200 performs the following two kinds ofdetections (determinations) for the uplink synchronization state withrespect to each user equipment terminal (UE) 100 _(n) in theRRC_connected state.

First, the base station apparatus (eNB) 200 performs power detection ofa Sounding RS (Reference signal) of the user equipment terminal (UE)within a range of Window 1 determined by taking the cell radius intoconsideration and having a similar size of a Window to wait for a RACHpreamble. Namely, when a metric used in the power detection of the userequipment terminal exceeds a predetermined threshold, the result of thepower detection is determined as OK. Otherwise, the result of the powerdetection is determined as NG. Further, a reflection time (which is atime period required to determine OK or NG) in the power detection istypically in a range from 200 ms to 1,000 ms while the Sounding RS iscontinuously received.

Second, the base station apparatus (eNB) 200 performs FFT timingdetection to detect whether a signal of the user equipment terminal (UE)is included within a range of Window 2 defined based on an FFT timingand a CP (Cyclic Prefix) length. Therefore, when the signal of the userequipment terminal (UE) is included in the Window 2, the result of theFFT timing detection is determined as OK. When there is no main path ofthe user equipment terminal (UE), the result of the FFT timing detectionis determined as NG. Further, the reflection time (which is a timeperiod required to determine OK or NG) in the FFT timing detection istypically in a range from 1 ms to 200 ms while the Sounding RS iscontinuously received.

The “Out of Synchronization: Type A” refers to a synchronization stateof the user equipment terminal (UE) in which the result of the powerdetection is determined as OK and the result of the FFT timing detectionis determined as NG. On the other hand, the “Out of Synchronization:Type B” refers to a synchronization state of the user equipment terminal(UE) in which the result of the power detection is determined as NG andthe result of the FFT timing detection is determined as NG.

As described above, the process of the HARQ Retransmission Check in stepS306 is performed before the process of the UL Sync Check in step S314.Accordingly, when the result of the HARQ Retransmission Check isdetermined as “Retransmission”, the retransmitted UL-SCH is receivedwith respect to the user equipment terminal (UE) even if the result ofthe UL Sync Check is determined as NG.

4.1.6. Received SIR Check

Next, in step S316, Received SIR Check is performed. In this step, whenthe base station apparatus 200 does not receive the reference signalfrom the user equipment terminal (UE), the base station apparatus 200does not allocate the Uplink Shared Channel (RBs for the Uplink SharedChannel) to the user equipment terminal (UE).

Specifically, the base station apparatus 200 determines whether at leastone Sounding Reference Signal is received from the user equipmentterminal (UE) within “all the RBs in which the Sounding Reference Signalmay be transmitted”, which is defined by the transmission bandwidth andthe frequency hopping interval for the Sounding Reference Signal. Whenat least one Sounding Reference Signal is received within “all the RBsin which the Sounding Reference Signal may be transmitted”, the processof the Received SIR Check returns OK. Otherwise, the process of theReceived SIR Check returns NG (failed). When the result of the ReceivedSIR Check is determined as NG, the user equipment terminal (UE) isexcluded from a target of the scheduling process.

In this example, the base station apparatus 200 determines whether atleast one Sounding Reference Signal is received within “all the RBs inwhich the Sounding Reference Signal may be transmitted”. Alternatively,the base station apparatus 200 may determine whether at least oneSounding Reference Signal is received in at least one of “all the RBs inwhich the Sounding Reference Signal may be transmitted”.

The Sounding Reference Signal refers to a signal used for measurement ofchannel quality for the purpose of uplink frequency scheduling.

4.1.7. Persistent Scheduling Check

Next, in step S318, Persistent Scheduling Check is performed. Persistentscheduling is a scheduling scheme for periodically allocating datatransmission opportunities in accordance with a data type or features ofthe application to transmit/receive data. Further, the data type mayinclude data of Voice Over IP, Streaming data or the like. The VoiceOver IP or the Streaming corresponds to the application.

In step S318, it is determined whether the user equipment terminal (UE)has a logical channel to which persistent scheduling is applied. When itis determined that the user equipment terminal (UE) has a logicalchannel to which persistent scheduling is applied, the process goes tostep S320 in which Persistent Scheduling Sub-frame Check is performed.Otherwise, the process goes to step S328 in which UL Low/High Fd Checkis performed.

4.1.7.1. Persistent Scheduling Sub-Frame Check

Next, in step S320, Persistent Scheduling Sub-frame Check is performed.In this step, it is determined whether persistent resources are to beallocated to the user equipment terminal's logical channel to whichpersistent scheduling is applied. When it is determined that persistentresources are to be allocated, the process goes to step S322 in whichAssign/Release Check is performed. Otherwise, the process goes to stepS328 in which UL Low/High Fd Check is performed. As used herein, thepersistent resources refer to resource blocks which are reserved forpersistent scheduling.

4.1.7.2. Assign/Release Check

Next, in step S322, Assign/Release Check is performed. It is determinedwhether the base station apparatus 200 receives from the user equipmentterminal (UE) a Release request for the persistent resources which areallocated to the user equipment terminal (UE) in the correspondingsub-frame. When the base station apparatus receives the Release request,the process goes to step S326 in which Persistent Resource Release isperformed. Otherwise, the process goes to step S324 in which PersistentResource Reservation is performed.

4.1.7.3. Persistent Resource Reservation

Next, in step S324, Persistent Resource Reservation is performed. Inthis step, persistent resources to be allocated to the user equipmentterminal's logical channel to which persistent scheduling is applied arereserved.

Further, Scheduling Coefficient Calculation described in Section 4.1.10is also performed with respect to the user equipment terminal (UE) towhich persistent resources are to be allocated in the correspondingsub-frame. Further, when radio resources are allocated to the logicalchannel to which dynamic scheduling is applied in the correspondingsub-frame, the user equipment terminal (UE) multiplexes the logicalchannel to which persistent scheduling is applied and the logicalchannel to which dynamic scheduling is applied, and then transmits theMAC PDU (UL-SCH).

Alternatively, radio resources may not be allocated to the logicalchannel to which dynamic scheduling is applied in the correspondingsub-frame with respect to the user equipment terminal (UE) to whichpersistent resources are to be allocated in the corresponding sub-frame.In this case, the process goes to step S336 after Persistent ResourceReservation in step S324.

4.1.7.4. Persistent Resource Release

Next, in step 326, Persistent Resource Release is performed. In thisstep, when the base station apparatus 200 receives a signal for therelease of the resources to be allocated according to persistentscheduling, the base station apparatus 200 uses the released resources(the resources to be allocated according to persistent scheduling) asthe resources to be allocated according to dynamic scheduling.

Specifically, the base station apparatus 200 releases persistentresources to be allocated in the corresponding sub-frame to the userequipment terminal's logical channel to which persistent scheduling isapplied. It should be noted that the persistent resources are releasedonly in the corresponding sub-frame and the Assign/Release Check isperformed again in the next allocation timing of persistent resources.

4.1.8. UL Low/High Fd Check

Next, in step S328, the uplink transmission type is checked (UL Low/HighFd Check is performed). In this step, it is determined whether the ULtransmission type for the user equipment terminal (UE) is Low Fd or HighFd. The transmission type is independently managed in downlink anduplink.

For example, when the value of path loss (Pathloss) for the userequipment terminal (UE) is less than or equal to a predeterminedthreshold (Threshold_(PL)) and when the estimated value of Fd for theuser equipment terminal (UE) is less than or equal to a predeterminedthreshold (Threshold_(Fd,UL)), the UL transmission type is determined asLow Fd. Otherwise, the UL transmission type is determined as High Fd.

As the value of Pathloss, a value reported from the user equipmentterminal (UE) by means of a Measurement report or the like may be used.Alternatively, as the value of Pathloss, a value calculated based onboth UPH (UE Power Headroom) reported from the user equipment terminal(UE) and the received level of the Sounding Reference Signal transmittedfrom the user equipment terminal (UE) may be used. When the value ofPathloss is calculated based on both the UPH reported from the userequipment terminal (UE) and the received level of the Sounding ReferenceSignal transmitted from the user equipment terminal (UE), the value ofPathloss may be calculated according to the following equation.

Pathlosss=(maximum transmission power for UE)−UPH−(the received level ofthe Sounding RS)

(This equation is calculated in the units of dB.)

UPH is defined as follows.

UPH=(maximum transmission power for UE)−(transmission power for theSounding RS)

(This equation is also calculated in the units of dB.)

As the estimated value of Fd, the value reported from the user equipmentterminal (UE) by means of the Measurement report or the like may beused. Alternatively, as the estimated value of Fd, a value calculatedbased on the time correlation value of the Sounding Reference Signaltransmitted from the user equipment terminal (UE) may be used.

Further, in this example, the transmission type is determined based onboth the value of Pathloss and the estimated value of Fd. Alternatively,the transmission type may be determined based on only the value ofPathloss or only the estimated value of Fd.

4.1.9. Buffer Status Check (Highest Priority)

Next, in step S330, Buffer Status Check is performed. In this step, thebase station apparatus does not allocate the Uplink Shared Channel (RBsfor the Uplink Shared Channel) to the user equipment terminal (UE), whenthe user equipment terminal (UE) does not have data to be transmitted.

Specifically, it is determined whether there are available data to betransmitted in the corresponding sub-frame with respect to the userequipment terminal's logical channel groups (a high priority group and alow priority group). When there are no available data to be transmitted,the process of the Buffer Status Check returns NG (failed). Otherwise,the process of the Buffer Status Check returns OK. As used herein,available data to be transmitted refers to available data to beinitially transmitted. When the amount of data in the UL Buffer isgreater than zero (0), it is determined that there are “available datato be initially transmitted”. Please refer to Section 4.1.10.2 for thedefinition of the amount of data in the UL Buffer. Although two types ofthe user equipment terminal's logical channel groups (the high prioritygroup and the low priority group) are used in this example, a similarprocess can be applied to the case where three or more types of logicalchannel groups are used. Also, a similar process can be applied to thecase where only one type of logical channel group is used.

When the base station apparatus receives from the user equipmentterminal (UE) “allocation request for the PUSCH: REQUESTING” by means ofthe Scheduling request and uplink radio resources (PUSCH) have not beenallocated to the user equipment terminal (UE) since the base stationapparatus has received the Scheduling request, namely, when the UplinkShared Channel (RBs for the Uplink Shared Channel) is not allocated tothe user equipment terminal (UE), the following scheduling process isperformed assuming that there are available data to be transmitted withrespect to the logical channel group corresponding to the high prioritygroup.

When the base station apparatus does not receive information about theamount of data in the buffer (data including the Buffer Status Report)at the reception timing of the PUSCH (the UL-SCH as the transportchannel), even though the base station apparatus (eNB) allocates uplinkradio resources (PUSCH) in response to the Scheduling request orallocates the Uplink Shared Channel (RBs for the Uplink Shared Channel),the base station again assumes that the base station apparatus receivesfrom the user equipment terminal (UE) the “allocation request for thePUSCH: REQUESTING” by means of the Scheduling request and uplink radioresources (PUSCH) have not been allocated to the user equipment terminal(UE) since the base station apparatus has received the Schedulingrequest. This assumption is made when the base station apparatus doesnot receive information about the amount of data in the buffer (dataincluding the Buffer Status Report) at the timing of initialtransmission without waiting for the maximum number of retransmissiontimes.

When the result of the Buffer Status Check is determined as NG, the userequipment terminal (UE) is excluded from a target of the schedulingprocess for initial transmission.

On the other hand, when the result of the Buffer Status Check isdetermined as OK, a logical channel group with the highest prioritylevel is selected based on the following selection logic and the processgoes to step S332 in which Scheduling Coefficient Calculation isperformed. In other words, the base station apparatus calculates thescheduling coefficients based on the data type with the highest prioritylevel among data types retained by the user equipment terminal.

Selection logic 1: When there are available data to be transmitted inthe high priority group, the logical channel group corresponding to thehigh priority group is defined as the logical channel group with thehighest priority level.

Selection logic 2: When there are no available data to be transmitted inthe high priority group (when there are available data to be transmittedonly in the low priority group), the logical channel group correspondingto the low priority group is defined as the logical channel group withthe highest priority level.

4.1.10. Scheduling Coefficient Calculation

Next, in step S332, Scheduling Coefficient Calculation is performed. Inthis step, with respect to the logical channel group with the highestpriority level determined in Section 4.1.9, the scheduling coefficientsare calculated based on the following evaluation equation.

Tables 1-1 and 1-2 show parameters set via the external interface (I/F).Table 2 shows parameters for each logical channel group of the userequipment terminal (UE).

TABLE 1-1 List of input parameters for the scheduler (The subscript LCGrefers to the logical channel group.) Set with respect No Parameter nameto each Remarks 1 A_(LCG) Logical This is a Priority channel Classpriority level group coefficient based on the logical channel group. 2F_(LCG)(t_(No) _(—) _(allocated)) Logical This is a transmission channelresource allocation group priority level coefficient used topreferentially transmit data to UE to which transmission resources arenot allocated according to dynamic scheduling. A time interval t_(No)_(—) _(allocated) during which transmission resources are not allocatedaccording to dynamic scheduling is defined as an elapsed time from thetiming when the preceding CRC result of the UL-SCH including logicalchannels belonging to the corresponding logical channel group isdetermined as OK. If the CRC result of the UL-SCH including logicalchannels belonging to the corresponding logical channel group is neverdetermined as OK, the time interval t_(No) _(—) _(allocated) is definedas an elapsed time from the timing when information about the amount ofdata in the buffer (the amount of data is other than zero (0)) withrespect to the logical channel group is reported from the user equipmentterminal. This value is set based on the buffer residence time t_(No)_(—) _(allocated) as follows. F_(LCG)(t_(No) _(—) _(allocated) <Th_(LCG) ^((No) ^(—) _(allocated))) = 0.0 F_(LCG)(t_(No) _(—)_(allocated) >= Th_(LCG) ^((No) ^(—) _(allocated))) = 1.0 3 Th_(LCG)^((No)__(Allocated)) Priority This is a threshold class related to thetime interval during which transmission resources are not allocatedaccording to dynamic scheduling. 4 G(flag_(SR)) UE This is a Schedulingrequest priority level coefficient given to preferentially transmit datato UE from which the base station apparatus receives “allocation requestfor the PUSCH: REQUESTING” by means of the Scheduling request and towhich uplink radio resources (PUSCH) have not been allocated since thebase station apparatus has received the Scheduling request. In thecorresponding sub-frame, this value is set based on a value flag_(SR)related to the corresponding UE. For example, when flag_(SR) = 0, G(0)is set to a fixed value 1.0 (G(0) = 1.0), and only when flag_(SR) = 1,this value is set via the external interface (I/F). When the basestation apparatus receives from the UE “allocation request for thePUSCH: REQUESTING” by means of the Scheduling request and when uplinkradio resources (PUSCH) have not been allocated to the UE since the basestation apparatus has received the Scheduling request, flag_(SR) is setequal to one (flag_(SR) = 1). Otherwise, flag_(SR) is set equal to zero(flag_(SR) = 0). 5 H(flag_(gap) _(—) _(control)) UE This is a gapcontrol priority level coefficient used to preferentially transmit datato UE in which a Measurement gap control mode is ON to measure a cellwith a different frequency. In the corresponding sub-frame, this valueis set based on a value flag_(gap) _(—) _(control) of the correspondingUE. When flag_(gap) _(—) _(control) = 0, H(0) is set to a fixed value1.0 (H(0) = 1.0), and only when flag_(gap) _(—) _(control) = 1, thisvalue is set via the external interface (I/F). When the corresponding UEis in Measurement gap control mode (i.e., when the Measurement gapcontrol mode is ON), flag_(gap) _(—) _(control) is defined as 1(flag_(gap) _(—) _(control) = 1), otherwise, flag_(gap) _(—) _(control)is defined as 0 (flag_(gap)__(control) = 0). For example, to increasethe priority level of UE where the Measurement gap control mode is ON,H(1) may be set 10 (H(1) = 10).

TABLE 1-2 List of input parameters for the scheduler (The subscript LCGrefers to the logical channel group.) Set with Parameter respect No nameto each Remarks 6 R_(PC) ^((target)) Logical This is a target datachannel rate (bits/sub-frame). group 7 α^((PL)) UE This is a weightingcoefficient with respect to the priority level based on path loss(Pathloss). 8 α_(LCG) ^((No) ^(—) ^(allocated)) Logical This is aweighting channel coefficient with respect group to the priority levelbased on the transmission interval during which transmission resourcesare not allocated according to dynamic scheduling. 9 α_(LCG) ^((freq))Logical This is a weighting channel coefficient with respect group tothe priority level based on the allocation frequency (the frequency ofallocation occurrences). 10 α_(LCG) ^((rate)) Logical This is aweighting channel coefficient with respect group to the priority levelbased on an Average Data Rate. 11 δ′_(LCG) Logical This is a convergencechannel value of a user data rate group averaged forgetting coefficientfor R _(n,k). 12 τ′ UE This is a convergence value of allocationfrequency averaged forgetting coefficient used in calculating freq_(n).13 Scheduling Cell This is a parameter to priority select a schedulingmode handling mode among logical channel groups. This value is set as avalue 0 or 1. 0 is a mode used to preferentially schedule the highpriority group regardless of the values of scheduling coefficients. 1 isa mode used to schedule based on the values of scheduling coefficients.

TABLE 2 List of input parameters for the scheduler (The subscript LCGrefers to the logical channel group.) Parameter No. name Remarks 1 R_(n)This parameter indicates an Instantaneous transmittable Data Rate(bits/sub-frame) of UE #n, as described below. This parameter iscalculated based on the following equation with reference to theUL_TF_related_table. R_(n) = UL_Table_TF_SIZE (RB_all,└SIR_(estimated)┘) where RB_all is the number of RBs across the systemband. Further, SIR_(estimated) is calculated across the system band.Alternatively, SIR_(estimated) may be the maximum value of plural setsof SIR_(estimated) which are calculated across narrower bands.Alternatively, SIR_(estimated) may be selected, based on thetransmission type, from both the value calculated across the system bandand the maximum value of plural sets of SIR_(estimated) which arecalculated across narrower bands. 2 R _(n,k) This parameter indicates anAverage Data Rate (bits/sub-frame) of a logical channel group #k of UE#n. R _(n,k) (TTI) = δ_(n,k) * R _(n,k) (TTI-1) + (1 − δ_(n,k)) *r_(n,k) r_(n,k): instantaneous data rate As the initial value of R_(n,k), R_(n,k) calculated in the sub-frame is used. δ_(n,k): forgettingcoefficient which is a variable changing for each calculation period, asdescribed in Section 4.1.10.1. Calculation of R _(n,k) is performed inevery sub-frame based on an updating timing (Section 4.1.10.1) withrespect to not only a logical channel group with the highest prioritylevel but also any other logical channel groups. 3 freq_(n) Thisparameter indicates a time- average value of allocation frequency of UE#n. An averaging interval (time) is designated by τ. Namely, Freq_(n) =τ_(n) * freq_(n) (TTI-1) + (1 − τ_(n,k)) * Allocated_(n), where,Allocated_(n) is set to be 1 when the DL-SCH is allocated to UE #n inthe sub-frame where the amount of data in the UL Buffer is not zero (0)for the high priority group or the low priority group of UE #n.Otherwise, Allocated_(n) is set to be 0. Further, the update is to beperformed in each sub- frame when the amount of data in the UL Buffer isnot zero (0). Calculation of freq_(n) is performed with respect to eachUE rather than with respect to each logical channel group. 4 Freq Thisparameter indicates a value by averaging freq_(n) among user equipmentterminals (UEs). Averaging is performed with respect to only userequipment terminals (UEs) in which the amount of data in the UL Bufferfor the high priority group or the low priority group is not zero (0) inthe corresponding sub-frame. Namely, it is calculated as follows.${Freq} = \frac{\sum\limits_{n,{Scheduling}}{freq}_{n}}{\sum\limits_{n,{Scheduling}}1}$${where}\mspace{14mu} {\sum\limits_{n,{Scheduling}}{{denotes}\mspace{14mu} {the}\mspace{14mu} {sum}\mspace{14mu} (\Sigma)}}$with respect to the “user equipment terminals (UEs) in which the amountof data in the UL Buffer for the high priority group or the low prioritygroup is not zero (0) in the corresponding sub- frame”.

Based on the input parameters in Tables 1-1, 1-2, and 2, the schedulingcoefficient C_(n) of the logical channel #h with the highest prioritylevel of the user equipment terminal (UE) #n is calculated according tothe following equation (1-1) ([Equation 1]).

[Equation 1]

C _(n) =A _(highest)×α^((PL)) ·R _(n)×(1+α_(highest) ^((No) ^(—)^(allocated)) ·F _(highest)(t _(No) _(—)_(allocated)))×G(flag_(SR))×exp(α_(highest)^((freq))·(Freq−freq_(n))+α_(highest) ^((rate))·(R _(n,highest)^((target)) − R _(n,highest)))  (1-1)

Namely, when the base station apparatus selects a user equipmentterminal to which radio resources are allocated, the base stationapparatus may select the user equipment terminal based on a signal(Scheduling request) by means of which the user equipment terminalrequests allocation of the Uplink Shared Channel (RBs for the UplinkShared Channel). In addition, the base station apparatus may calculate acoefficient representing a priority level for allocating radio resourcesbased on at least one of a priority class of data; radio quality of thereference signal transmitted from the user equipment terminal (forexample, SIR of the Sounding Reference Signal); a time duration duringwhich the shared channel (RBs for the shared channel) is not allocated;whether the base station apparatus receives the Scheduling request; afrequency of allocation occurrences; an average transmission rate; and atarget transmission rate.

Alternatively, the scheduling coefficient C_(n) of the logical channel#h with the highest priority level of the user equipment terminal (UE)#n may be calculated according to the following equation (1-2)([Equation 2])

[Equation 2]

C _(n) =A _(highest)×α^((PL)) ·R _(n)×(1+α_(highest) ^((No) ^(—)^(allocated)) ·F _(highest)(t _(No) _(—)_(allocated)))×G(flag_(SR))×H(flag_(gap) _(—)_(control))×exp(α_(highest) ^((freq))·(Freq−freq_(n))+α_(highest)^((rate))·(R _(n,highest) ^((target)) − R _(n,highest)))  (1-2)

In the equation (1-2), a term of “H (flag_(gap) _(—) _(control))” isadded to the equation (1-2). flag_(gap) _(—) _(control) is a flagindicating whether the user equipment terminal (UE) #n is in aMeasurement gap control mode. As used herein, the Measurement gapcontrol mode indicates whether a Measurement gap for measuring a cellwith a different frequency is being applied. When the Measurement gapcontrol mode is ON, the Measurement gap is set at a predeterminedtiming. The Measurement gap is set by the base station apparatus 200.

Generally, in the sub-frame where the Measurement gap is applied, datacannot be transmitted and received. Therefore, it is necessary toallocate radio resources to the user equipment terminal (UE) #n topreferentially transmit and receive data in the sub-frame to which theMeasurement gap is not applied. For example, by setting H(flag_(gap)_(—) _(control)) to be 10 (H(flag_(gap) _(—) _(control))=10) in the caseof flag_(gap) _(—) _(control)=1 (i.e., Measurement gap control mode: ON)and H(flag_(gap) _(—) _(control)) is set to be 1 (H(flag_(gap) _(—)_(control))=1) in the case of flag_(gap) _(—) _(control)=0 (i.e.,Measurement gap control mode: OFF), it may become possible to“preferentially transmit and receive data in the sub-frame to which theMeasurement gap is not applied”.

By the Measurement Gap Check in step S310, when the Measurement gapcontrol mode is ON and when the time frame in which the PhysicalDownlink Control Channel for the Uplink Shared Channel is transmitted indownlink is included in the Measurement gap or the time frame in whichthe shared channel is received or the time frame in which acknowledgeinformation for the Uplink Shared Channel is transmitted is included theMeasurement gap, this process in step S332 is not performed. In otherwords, when the Measurement gap control mode is ON and when this processin step S332 is to be performed, the sub-frame is at the timing when thesame (original) frequency signal is transmitted and received in a modewhen a cell with a different frequency is being measured. Namely, due tothe term “H(flag_(gap) _(—) _(control))”, it may become possible topreferentially allocate the shared channel to the user equipmentterminal transmitting and receiving the same (original) frequency in amode when a cell with a different frequency is being measured.

In the case of intra-eNB handover (Intra-eNB HO), measured values andcalculated values used for the scheduling process are transferred to aTarget eNB (eNB of the handover destination).

4.1.10.1. Measurement of Average Data Rate

In step S332, an Average Data Rate is measured. The Average Data Rate iscalculated using the following equation (2) ([Equation 3]).

[Equation 3]

R _(n,k) =R _(n,k)(N _(n,k)=1)

R _(n,k)=δ_(n,k) · R _(n,k)·(TTI−1)+(1−δ_(n,k))·r _(n,k)(N_(n,k)>1)  (2)

where N_(n,k)(1, 2, . . . ) denotes the number of times updating theAverage Data Rate. However, in the sub-frame where N_(n,k)=0, thefollowing equation (3) ([Equation 4]) is applied.

[Equation 4]

R_(n,k)=R_(n,k)  (3)

Further, a forgetting coefficient δ_(n,k) is calculated as follows.

δ_(n,k)=min(1−1/N _(n,k)δ′_(PCn,k))

An updating cycle of the Average Data Rate is based on “every sub-framewhere the amount of data in the UL Buffer is not zero (0) for eachlogical channel group”. Further, r_(n,k) is calculated as “the size ofthe MAC SDU (including for both initial transmission and retransmission)transmitted from the user equipment terminal (UE)”. Namely thecalculation of the Average Data Rate is performed based on any of thefollowing operations in the sub-frame when the Average Data Rate is tobe updated.

1) For a user equipment terminal (UE) that transmits data, the AverageData Rate is calculated assuming “r_(n,k)=size of the transmitted MACSDU”.

2) For a user equipment terminal (UE) that has not transmitted data, theAverage Data Rate is calculated assuming “r_(n,k)=0”.

The size of the retransmitted MAC SDU is calculated retroactively toprevious transmissions of the UL-SCH, when the CRC result of the UL-SCHincluding logical channels belonging to the corresponding logicalchannel group is OK.

It should be noted that the Average Data Rate is calculated when theresult of the Received SIR Check is OK and the condition of updating theAverage Data Rate is matched. Namely the calculation is started after atleast one Sounding Reference Signal is received across the whole band.

4.1.10.2. Definition of the Amount of Data in UL MAC

The amount of data in the UL Buffer is defined as follows.

The amount of data Buffer_(n,k) ^((UL)) in the UL Buffer for a logicalchannel group #k of the user equipment terminal (UE) #n is calculated asfollows.

$\begin{matrix}\left\lbrack {{Equation}\mspace{14mu} 5} \right\rbrack & \; \\{{Buffer}_{n,k}^{({UL})} = {{Buffer}_{n,k}^{({BSR})} - {\sum\limits_{j}{{Size}_{n,k}^{({{CRC}:{OK}})}(j)}}}} & (4)\end{matrix}$

where Buffer_(n,k) ^((BSR)) denotes the amount of data in the buffer forthe logical channel group #k of the user equipment terminal (UE) #n,which is calculated based on the Buffer Status Report reported from theuser equipment terminal (UE).

$\sum\limits_{j}{{Size}_{n,k}^{({{CRC}:{OK}})}(j)}$

denotes the sum of data sizes for the logical channel group #k of theuser equipment terminal (UE) #n, which has been included in the UL-SCHwhere the CRC result is OK since the timing of making the Buffer StatusReport (until the current timing).

Namely, the base station apparatus calculates the amount of data in thebuffer of the user equipment terminal based on both information aboutthe amount of data in the buffer (Buffer Status Report (BSR)) reportedfrom the user equipment terminal and the amount of data which has beenreceived from the user equipment terminal since the base stationapparatus has received the information.

4.1.11. UE Selection

Next, in step S334, N_(Scheduling) indicating the number of userequipment terminals (UEs) for which the scheduling coefficient iscalculated is incremented by one. In step S336, a value of “n”indicating the index of the user equipment terminal (UE) is incrementedby one.

Next, in step S338, it is determined whether the value of “n” is lessthan or equal to N. When it is determined that the value of “n” is lessthan or equal to N, the process goes back to step S304.

On the other hand, when it is determined that the value of “n” isgreater than N, the process goes to step S340 in which UE Selection isperformed. In this step, the user equipment terminal (UE) to which radioresources are to be allocated according to dynamic scheduling (only forinitial transmission) is selected in the corresponding sub-frame.

First, according to the following equation, the number of user equipmentterminals (UEs) N_(UL-SCH) to which radio resources are to be allocatedaccording to dynamic scheduling is calculated. N_(Scheduling) denotesthe number of user equipment terminals (UEs) for which the schedulingcoefficient is calculated (see FIG. 3). N_(retransmission) denotes thenumber of user equipment terminals (UEs) which perform retransmission inthe corresponding sub-frame (see FIG. 3).

N _(UL-SCH,tmp)=min(N _(Scheduling) ,N _(ULMAX) −N _(retransmission))

Then, the “user equipment terminals (UEs) to which radio resources areto be allocated according to dynamic scheduling” are selected as followsbased on the value of the Scheduling priority handling mode.

If the Scheduling priority handling mode=0;

Top N_(UL-SCH) “user equipment terminals (UEs) to which radio resourcesare to be allocated according to dynamic scheduling” are selected indescending order of the scheduling coefficients calculated in Section4.1.10 for each logical channel group, by prioritizing the high prioritygroups. Namely, the user equipment terminals (UEs) are selectedaccording to the following order.

High (1st)->High (2nd)-> . . . ->Low (1st)->Low (2nd)-> . . .

If the Scheduling priority handling mode=1;

Top N_(UL-SCH) “user equipment terminals (UEs) to which radio resourcesare to be allocated according to dynamic scheduling” are selected indescending order of the scheduling coefficients calculated in Section4.1.10 regardless of the logical channel group.

As described above, it may become possible to calculate the schedulingcoefficient with respect to each user equipment terminal that isdetermined to be capable of initial transmission, by performing a loopprocess with respect to “n” which is an index of the user equipmentterminals (UE index). Further, the radio resources may be allocated tothe user equipment terminal having a greater calculated schedulingcoefficient value, and thereby it may become possible to determine theuser equipment terminals to which the radio resources (Uplink SharedChannel) are to be allocated based on a priority level of data; uplinkradio quality; a time duration during which the shared channel (RBs forthe shared channel) is not allocated; whether the base station apparatusreceives the Scheduling request; a frequency of allocation occurrences;an average transmission rate; or a target transmission rate.

5. UL TFR Selection

Next, Uplink TFR Selection (UL TFR Selection) performed in step S208 isdescribed with reference to FIG. 4.

FIG. 4 shows a procedure of UL TFR Selection. According to thisprocedure, the base station apparatus 200 reserves radio resources (RBs)for the Physical Random Access Channel (PRACH), reserves prohibitedradio resources (RBs) or guard RBs, reserves radio resources (RBs) forthe UL-SCH to which persistent scheduling is applied, and thendetermines a transmission format for the UL-SCH to which dynamicscheduling is applied and allocates radio resources for the UL-SCH towhich dynamic scheduling is applied (including for both initialtransmission and retransmission).

5.1. RB Allocation for PRACH and PUCCH

In step S402, resource block allocation for the Physical Random AccessChannel (PRACH) and the Physical Uplink Control Channel (PUCCH) to befrequency-multiplexed with the Physical Uplink Shared Channel (PUSCH)(RB allocation for PRACH and PUCCH) is performed. In this step, radioresources are allocated to the Random Access Channel (RACH) and thePhysical Uplink Control Channel (PUCCH) before radio resources areallocated to the shared channel.

Specifically, when a RACH preamble is transmitted in the correspondingsub-frame, radio resources (RBs) for the PRACH and N_(RACH) RBs on bothsides of the PRACH are reserved (6+2*N_(RACH) RBs are reserved intotal). In other words, the radio resources (RBs) for the PRACH andN_(RACH) RBs on both sides of the PRACH (6+2*N_(RACH) RBs in total) areexcluded from candidates for RBs to be allocated to the UL-SCH to whichdynamic scheduling is applied. For example, N_(RACH) is a valuedesignated via the external input interface (I/F). For example, N_(RACH)is selected from 0, 1, 2, and 3.

The PRACH preamble corresponds to a Message-1 in the random accessprocedure. The number of resource blocks in which the PRACH preamble istransmitted is equal to six (6).

In addition, radio resources (RBs) for the Physical Uplink ControlChannel (PUCCH) are reserved. In other words, the radio resources (RBs)to be allocated to the Physical Uplink Control Channel (PUCCH) areexcluded from candidates for RBs to be allocated to the UL-SCH to whichdynamic scheduling is applied.

5.2. RB Allocation for Guard RBs

In step S404, RB allocation for Guard RBs is performed. When the systemis frequency-adjacent (adjacent in the frequency direction) to aheterogeneous radio communication system (WCDMA system), for example,radio resources other than the resource placed at the end of the systembandwidth are allocated.

Specifically, Guard RBs are reserved. In other words, the Guard RBs areexcluded from candidates for RBs to be allocated to the UL-SCH to whichdynamic scheduling is applied.

In this example, the heterogeneous radio communication system is theWCDMA system. Alternatively, the heterogeneous radio communicationsystem may be a GSM system, a CDMA-2000 system, a PHS system, or thelike.

The Guard RBs are implemented as guard bands for the purpose of reducingadjacent channel interference with a frequency-adjacent system. Two setsof Guard RBs may be reserved for both ends of adjacent systems. Itshould be noted that the Physical Uplink Control Channel (PUCCH) ismapped to the end of the system band regardless of the presence orabsence of the Guard RBs.

5.3. RB Allocation for Persistent Scheduling

In step S406, RB allocation for Persistent Scheduling is performed. Inthis step, allocation according to persistent scheduling is performedbefore allocation according to dynamic scheduling is performed.

Specifically, radio resources (RBs) for the persistent resources, whichare reserved in Section 4.1.7.3, are reserved.

When persistent resources are allocated in the corresponding sub-frameto the “user equipment terminal (UE) to which radio resources are to beallocated according to dynamic scheduling (only for initialtransmission)”, the persistent resources are released. The RBscorresponding to the persistent resources are used for UL TFR Selectionfor the UL-SCH to which dynamic scheduling is applied. Please refer toSection 4.1.2 for the process where persistent resources are allocatedto the user equipment terminal (UE) for retransmission.

The base station apparatus may perform the following three processes, inorder to handle collisions from plural user equipment terminals (UEs)via the PUSCH due to either “miss detection of the UL Scheduling Grantvia the Physical Downlink Control Channel” or “false detection ofacknowledgement information (UL ACK/NACK) for the Uplink Shared Channel(False ACK (NACK->ACK) detection)” by the user equipment terminal (UE).

(1) In the case where radio resources (RBs) for dynamic scheduling whichare allocated to the “user equipment terminal (UE) to which radioresources are allocated according to dynamic scheduling (including forboth initial transmission and retransmission) and persistent resourcesare also allocated” include all of the RBs corresponding to the radioresources (RBs) for the persistent resources;

First, the base station apparatus performs reception of the UL-SCH fromthe user equipment terminal (UE) according to dynamic scheduling at thereception timing. Then, when the CRC result is NG, the base stationapparatus performs reception of the UL-SCH according to persistentscheduling.

(2) In the case where radio resources (RBs) for dynamic scheduling whichare allocated to the “user equipment terminal (UE) to which radioresources are allocated according to dynamic scheduling and persistentresources are also allocated” include none of the RBs corresponding tothe radio resources (RBs) corresponding to the persistent resources;

First, the base station apparatus performs reception of the UL-SCH fromthe user equipment terminal (UE) according to dynamic scheduling at thereception timing. Then, when the result of the power detection is DTX(when no transmission of the UL-SCH is detected), the base stationapparatus performs reception of the UL-SCH according to persistentscheduling.

When the radio resources (RBs) for persistent scheduling are found tocollide with “radio resources (RBs) which are allocated to other userequipment terminals (UEs) according to dynamic scheduling” and when theCRC result for the “radio resources (RBs) which are allocated to otheruser equipment terminals (UEs) according to dynamic scheduling” is NG,the base station apparatus transmits the ACK for the “UL-SCH accordingto persistent scheduling” to the user equipment terminal (UE) regardlessof the CRC result.

(3) In the case other than (1) and (2);

First, the base station apparatus performs reception of the UL-SCHaccording to dynamic scheduling at the reception timing. Then, the basestation apparatus performs power detection using only RBs which do notoverlap the radio resources (RBs) corresponding to the persistentresources. When the result of the power detection is DTX (when notransmission of the UL-SCH is detected), the base station apparatusperforms reception of the UL-SCH according to persistent scheduling.

When the radio resources (RBs) for persistent scheduling are found tocollide with “radio resources (RBs) which are allocated to other userequipment terminals (UEs) according to dynamic scheduling” and when theCRC result for the “radio resources (RBs) which are allocated to otheruser equipment terminals (UEs) according to dynamic scheduling” is NG,the base station apparatus transmits the ACK for the “UL-SCH accordingto persistent scheduling” to the user equipment terminal (UE) regardlessof the CRC result.

5.4. Resource Block Allocation for the Message-3 in the Random AccessProcedure (RB Allocation for Message-3 (RACH))

In step S408, resource block allocation for the Message-3 in the randomaccess procedure (RB allocation for Message-3 (RACH)) is performed. Inthis step, radio resources are allocated to the Message-3(s) in therandom access procedure before radio resources are allocated to theshared channel.

Radio resources (RBs) for the Message-3s in the random access procedureare reserved. Specifically, radio resources (RBs) for the Message-3s inthe random access procedure (including for both initial transmission andretransmission) are excluded from candidates for RBs to be allocated tothe UL-SCH to which dynamic scheduling is applied.

In the following descriptions, the Message-3s in the random accessprocedure are merely referred to as Message-3s.

The RB allocation for the Message-3s for initial transmission isperformed according to the following five-step procedure. The RBallocation for retransmission is the same as the RB allocation forinitial transmission.

(1) It is determined whether there are available RBs to be allocated tothe Message-3s. When there are available RBs to be allocated to theMessage-3s, next step (2) is performed. Otherwise, this process comes toan end. The “available RBs to be allocated to the Message-3s” correspondto RBs other than the RBs allocated to the Physical Random AccessChannel (PRACH) and the Physical Uplink Control Channel (PUCCH), theGuard RBs, and the RBs allocated to the UL-SCH to which persistentscheduling is applied.

(2) Message-3s to be transmitted in the corresponding sub-frame arearranged in ascending order of quality. The order of plural Message-3swith the same quality is arbitrarily determined. The Message-3 withlowest quality is indexed as #0, and thereby the Message-3s are indexedas #0, #1, #2, #3, . . . .

(3) The following process is performed according to a Hopping mode.

The Hopping mode is a parameter designated via the external inputinterface (I/F).

If the Hopping mode is zero (Hopping mode==0), the base stationapparatus generates Message-3 sets, each of which includes a pair of twoMessage-3s selected on a two-by-two basis from the beginning ofMessage-3s in the order of #0, #1, #2, #3, . . . . The Message-3 setsare indexed as #a, #b, #c, . . . (the Message-3 set #a includes theMessage-3s #0 and #1, the Message-3 set #b includes the Message-3s #2and #3, and so on). When the number of Message-3s is odd-numbered, thelast Message-3 constitutes one Message-3 set.

The base station apparatus allocates “RBs which have reflective symmetryat the center of the system band” to the Message 3 sets in the order of#a, #b, #c, . . . . Specifically, the base station apparatus allocatesRBs to the Message-3 sets in the order of #a, #b, #c, . . . beginningfrom the ends of the system band. The number of RBs allocated to theMessage-3s is determined based on quality information. For example, whenthe quality information indicates “high quality”, two RBs are allocated.For example, when the quality information indicates “low quality”, fourRBs are allocated. Alternatively, the number of RBs may be determinedregardless of quality information. For example, this quality informationis included in the Message-1 in the random access procedure.

When the number of RBs in one Message-3 in a particular Message-3 set isdifferent from the number of RBs in the other Message-3 in theparticular Message-3 set, the base station apparatus uses a largernumber of RBs to allocate the “RBs which have reflective symmetry at thecenter of the system band”.

The base station apparatus 200 may notify the user equipment terminalthat the Message-3s are transmitted with hopping, as informationincluded in the Uplink Scheduling Grant to be mapped to the PhysicalDownlink Control Channel (PDCCH), for example.

The base station apparatus does not allocate RBs which are placedoutside the RBs allocated to the Message-3s to the UL-SCH to whichdynamic scheduling is applied. In addition, when the number ofMessage-3s is odd-numbered, the base station apparatus does not allocatethe RBs used for transmitting the last Message-3 to the UL-SCH to whichdynamic scheduling is applied.

Otherwise (if the Hopping mode is not zero), the base station apparatusallocates RBs to Message-3s as follows. The number of RBs allocated tothe Message-3s is determined based on quality information. For example,when the quality information indicates “high quality”, two RBs areallocated. For example, when the quality information indicates “lowquality”, four RBs are allocated. Alternatively, the number of RBs maybe determined regardless of quality information. For example, thisquality information is included in the Message-1 in the random accessprocedure.

#0: #0 is allocated to the RB with the lowest frequency among availableRBs to be allocated to the Message-3s;

#1: #1 is allocated to the RB with the highest frequency among availableRBs to be allocated to the Message-3s;

#2: #2 is allocated to the RB with the next lowest frequency amongavailable RBs to be allocated to the Message-3s;

#3: #3 is allocated to the RB with the next highest frequency amongavailable RBs to be allocated to the Message-3s; and so on.

(This process continues until RBs are allocated to all the Message-3s.)

(4) The modulation scheme for all the Message-3s is determined as QPSK.

(5) Transmission power of the Uplink Scheduling Grant for each Message-3is determined based on quality information. For example, when thequality information indicates “high quality”, transmission power isdetermined as low transmission power. For example, when the qualityinformation indicates “low quality”, transmission power is determined ashigh transmission power. Alternatively, transmission power may bedetermined regardless of quality information. For example, this qualityinformation is included in the Message-1 in the random access procedure.

When no more RBs can be allocated to the Message-3s during this process,the process comes to an end. The base station apparatus does nottransmit a Message-2 (RACH response) in the random access procedure tothe user equipment terminal (UE) which has the Message-3 to which no RBis allocated. Alternatively, the base station apparatus may transmit theMessage-2 (RACH response) in the random access procedure in the nextsub-frame.

In step S412, the value of “j” is set equal to 1 (j=1).

5.5. RB Remaining Check

In step S410, RB Remaining Check is performed. It is determined whetherthere are available RBs to be allocated to the UL-SCH to which dynamicscheduling is applied. When there are available RBs to be allocated tothe UL-SCH, the process of the RB Remaining Check returns OK. Otherwise,the process of the RB Remaining Check returns NG (failed). When theresult of the RB Remaining Check is determined as NG, the process of theUL TFR Selection comes to an end.

The “available RBs to be allocated to the UL-SCH to which dynamicscheduling is applied” correspond to RBs other than the RBs allocated tothe Physical Random Access Channel (PRACH) and the Physical UplinkControl Channel (PUCCH), the Guard RBs, the RBs allocated to the UL-SCHto which persistent scheduling is applied, the RBs allocated to theMessage-3 in the random access procedure, and the RBs allocated to theUL-SCH to which dynamic scheduling is applied after TFR Selection(including for both retransmission and initial transmission). The totalnumber of “available RBs to be allocated to the UL-SCH to which dynamicscheduling is applied (including for both retransmission andtransmission” is defined as N_(remain) ^((RB)).

The RBs allocated to the UL-SCH to which dynamic scheduling is appliedafter TFR Selection (including for both retransmission and initialtransmission) correspond to the RBs determined in step S414, when thevalue of “j” is less than the current value in the loop process withrespect to the index “j” composed of steps S410, S414, S416, and S418.

5.6. UL TFR Selection

In step S414, UL TFR Selection is performed. The base station apparatusdetermines the transport format for the “user equipment terminal (UE) towhich radio resources are to be allocated according to dynamicscheduling”, which is determined in Section 3.2, and allocates RBs.

5.6.1. Setting of RB Allocation Mode

In step S414, Setting of RB allocation mode is performed. The UL RBallocation mode shown in Table 3 is a parameter designated via theexternal input interface (I/F). The loop process with respect to theindex “j” is executed based on the selection order of user equipmentterminals (UEs) specified by the UL RB allocation mode.

TABLE 3 UL RB allocation mode Mode Definition Mode-0 This is a normal RBallocation mode. In this mode, the following selection order of userequipment terminals (UEs) is used. (1st criterion) User equipmentterminals (UEs) for retransmission are selected. Among these userequipment terminals (UEs), a higher selection order is assigned to auser equipment terminal (UE) with a longer elapsed time from initialtransmission. When the elapsed time is the same for plural userequipment terminals (UEs), the selection order is arbitrary determined.(2nd criterion) User equipment terminals for initial transmission areselected. Among these user equipment terminals (UEs), a higher selectionorder is assigned to the “candidates for the user equipment terminals(UEs) to which radio resources are to be allocated according to dynamicscheduling” determined in Section 4.1.11. Mode-1 This is a RB allocationmode in which RBs at the end of the system band are allocated to userequipment terminals with low path loss (Pathloss). (1st criterion) Userequipment terminals for retransmission are selected. Among these userequipment terminals (UEs), a higher selection order is assigned to auser equipment terminal (UE) with lower path loss. (2nd criterion) Userequipment terminals for initial transmission are selected. Among theseuser equipment terminals (UEs), a higher selection order is assigned toa user equipment terminal (UE) with lower path loss. Mode-2 This is a RBallocation mode in which RBs with a low frequency are allocated to userequipment terminals with high path loss (Pathloss). (1st criterion) Userequipment terminals for retransmission are selected. Among these userequipment terminals (UEs), a higher selection order is assigned to auser equipment terminal (UE) with higher path loss. (2nd criterion) Userequipment terminals for initial transmission are selected. Among theseuser equipment terminals (UEs), a higher selection order is assigned toa user equipment terminal (UE) with higher path loss. Mode-3 This is aRB allocation mode in which RBs with high frequency are allocated touser equipment terminals with high path loss (Pathloss). (1st criterion)User equipment terminals for retransmission are selected. Among theseuser equipment terminals (UEs), a higher selection order is assigned toa user equipment terminal (UE) with higher path loss. (2nd criterion)User equipment terminals for initial transmission are selected. Amongthese user equipment terminals (UEs), a higher selection order isassigned to a user equipment terminal (UE) with higher path loss.

For example, when the system is frequency-adjacent to a WCDMA system atone end and to an LTE system at the other end, Mode-2 and Mode-3 areselected. Specifically, when the system is frequency-adjacent to theWCDMA system at one end and to the LTE system at the other end, the basestation apparatus allocates radio resources (frequency resources) forthe shared channel, on the side of the WCDMA system and at the end ofthe system band, to a user equipment terminal with lower path loss. Inaddition, the base station apparatus allocates radio resources(frequency resources), on the side of the LTE system and at the end ofthe system band, to a user equipment terminal with higher path loss.

For example, when the system is frequency-adjacent to WCDMA systems atboth ends, Mode-1 is selected. Specifically, the base station apparatusallocates radio resources (frequency resources) for the shared channel,at both ends of the system band, to a user equipment terminal with lowerpath loss. In addition, the base station apparatus allocates radioresources (frequency resources), at the center of the system band, to auser equipment terminal with higher path loss.

For example, when the system is frequency-adjacent to LTE systems atboth ends, Mode-0 is selected. Specifically, radio resources (frequencyresources) are allocated based on reception power of the referencesignal transmitted from the user equipment terminal or the like, asdescribed below.

5.6.2. RB Allocation

In step S414, RB allocation is performed. According to the followingprocess, RBs are allocated to a j^(th) “user equipment terminal (UE) towhich radio resources are to be allocated according to dynamicscheduling”. FIG. 5 shows an example of a TF_Related_table.

As shown in FIG. 5, the TF_Related_table may store the correspondencebetween radio resources available for transmission of the Uplink SharedChannel, uplink radio quality information, and a transmission schemeused for transmission of the Uplink Shared Channel. The base stationapparatus may determine the transmission scheme used for the UplinkShared Channel, with reference to the TF_related_table, based on radioquality of the Sounding Reference Signal transmitted from the userequipment terminal (radio quality information calculated based on SIR,for example) and radio resources available for transmission of theUplink Shared Channel. In addition, the RF_Related_table may store thedata size used for the Uplink Shared Channel. The data size isdetermined to be a maximum value which satisfies a predetermined errorrate, when uplink radio quality information and frequency resourcesavailable for the shared channel are fixed. The TF_Related_table maystore, as the transmission scheme, the data size used for transmissionof the Uplink Shared Channel, a modulation scheme used for the UplinkShared Channel, and the amount of frequency resources used for theUplink Shared Channel.

<Process>

(Process of Calculating Temporary RBs)

N_(remain) ^(RB)): the number of Remaining RBs

N_(capability): the maximum number of RBs which is determined based onthe UE category

N_(max,bit): the maximum data size (payload size) which is determinedbased on the UE category

N _(remain) ^((UE)) =N _(UL-SCH) −j+1

$\begin{matrix}\left\lbrack {{Equation}\mspace{14mu} 6} \right\rbrack & \; \\{N_{allocated} = {\min\left( {\left\lceil \frac{N_{remain}^{({RB})}}{N_{{remain}\;}^{({UE})}} \right\rceil,N_{capability}} \right)}} & (5)\end{matrix}$

It is assumed that available RBs to be allocated to the j^(th) “userequipment terminal (UE) to which radio resources are to be allocatedaccording to dynamic scheduling” are continuous. When the RBs are notcontinuous, the “available RBs to be allocated” are determined as a setof RBs which has the maximum number of available RBs to be allocatedamong continuous available RBs to be allocated. When there are pluralsets of RBs which have the maximum number of available RBs to beallocated, the “RBs to be allocated” are determined as a set of RBs witha lower frequency.

When the number of subcarriers corresponding to N_(allocated) includesfactors other than 2, 3, and 5, N_(allocated) is determined as a maximuminteger among integers which include only factors of 2, 3, 5 for thenumber of subcarriers and which are less than N_(allocated).

(1) If the UL RB allocation mode==Mode-0 and UL Transmission type==HighFd;

RBs are allocated to the user equipment terminal (UE) among the“available RBs to be allocated to the UL-SCH to which dynamic scheduling(hereinafter called “available RBs to be allocated”)”, which aredetermined in Section 5.5, beginning from the lowest frequency or thehighest frequency until the number of RBs to be allocated to the userequipment terminal (UE) is greater than or equal to N_(allocated). Inthis case, hopping is not used.

<For Initial Transmission>

Upon determining whether RBs are allocated beginning from the lowestfrequency or the highest frequency, the base station apparatus selectsRBs far from the center of the system band. When RBs have the samedistance from the center of the system band, the base station apparatusallocates RBs beginning from the lowest frequency.

<For Retransmission>

Upon determining whether RBs are allocated beginning from the lowestfrequency or the highest frequency, the base station apparatusdetermines as follows based on whether the RBs include the previouslyallocated RBs.

N_(small) denotes the number of the previously allocated RBs, which areincluded in a set of RBs when the RBs are allocated beginning from thelowest frequency.

N_(large) denotes the number of the previously allocated RBs, which areincluded in a set of RBs when the RBs are allocated beginning from thehighest frequency.

If N_(small)>N_(large), RBs are allocated beginning from the highestfrequency.

If N_(small)=<N_(large), RBs are allocated beginning from the lowestfrequency.

For example, when the base station apparatus allocates frequencyresources (RBs) to the shared channel used by plural user equipmentterminals, beginning from the end of the system bandwidth, the basestation apparatus may allocate, to the shared channel used by the pluraluser equipment terminals, frequency resources (RBs) for retransmissionat one end of the system bandwidth which are different from thefrequency resources (RBs) used for previous transmission at the otherend of the system bandwidth.

(2) If the UL RB allocation mode==Mode-0 and UL Transmission type==LowFd;

RBs are allocated to the user equipment terminal (UE) among the“available RBs to be allocated to the UL-SCH to which dynamic schedulingis applied (hereinafter called “available RBs to be allocated”)”, whichare determined in Section 5.5, beginning from the lowest frequency orthe highest frequency until the number of RBs to be allocated to theuser equipment terminal (UE) is greater than or equal to N_(allocated).In this case, hopping is not used.

Upon determining whether RBs are allocated beginning from the lowestfrequency or the highest frequency, the base station apparatus selectsRBs as follows.

If SIR_(estimated) in the case where RBs are allocated beginning fromthe lowest frequency is higher than SIR_(estimated) in the case whereRBs are allocated beginning from the highest frequency, RBs areallocated beginning from the lowest frequency.

If SIR_(estimated) in the case where RBs are allocated beginning fromthe lowest frequency is lower than or equal to SIR_(estimated) in thecase where RBs are allocated beginning from the highest frequency, RBsare allocated beginning from the highest frequency.

For example, when the base station apparatus allocates frequencyresources (RBs) to the shared channel used by plural user equipmentterminals, beginning from the end of the system bandwidth, the basestation apparatus may allocate, to the shared channel used by the pluraluser equipment terminals, a frequency resource (RB) with higher radioquality among frequency resources (RBs) at both ends of the systembandwidth.

This process is used for both initial transmission and retransmission.

(3) If the UL RB allocation mode==Mode-1;

RBs are allocated to the user equipment terminal (UE) among the“available RBs to be allocated to the UL-SCH to which dynamic schedulingis applied (hereinafter called “available RBs to be allocated”)”, whichare determined in Section 5.5, beginning from the lowest frequency orthe highest frequency until the number of RBs to be allocated to theuser equipment terminal (UE) is greater than or equal to N_(allocated).In this case, hopping is not used.

Upon determining whether RBs are allocated beginning from the lowestfrequency or the highest frequency, the base station apparatus selectsRBs far from the center of the system band. When RBs have the samedistance from the center of the system band, the base station apparatusallocates RBs beginning from the lowest frequency.

(4) If the UL RB allocation mode==Mode-2;

RBs are allocated to the user equipment terminal (UE) among the“available RBs to be allocated to the UL-SCH to which dynamic schedulingis applied (hereinafter called “available RBs to be allocated”)”, whichare determined in Section 5.5, beginning from the lowest frequency untilthe number of RBs to be allocated to the user equipment terminal (UE) isgreater than or equal to N_(allocated). In this case, hopping is notused.

(5) If the UL RB allocation mode is anything other than Mode-0, Mode-1,and Mode-2;

RBs are allocated to the user equipment terminal (UE) among the“available RBs to be allocated to the UL-SCH to which dynamic schedulingis applied (hereinafter called “available RBs to be allocated”)”, whichare determined in Section 5.5, beginning from the highest frequencyuntil the number of RBs to be allocated to the user equipment terminal(UE) is greater than or equal to N_(allocated). In this case, hopping isnot used.

In this process, a set of RBs “to be allocated to the user equipmentterminals (UE)” is called a Temporary RB group. SIR_(i,estimated) in theTemporary RB group is defined as SIR_(estimated) ^(RB)).

When the user equipment terminal performs retransmission of the UL-SCHand when the Uplink Scheduling Grant for retransmission is notspecified, this process is not performed. Instead, the base stationapparatus allocates, to the UL-SCH for retransmission, the same RBs asthe RBs used for the previous transmission.

[Calculation for SIR_(estimated)]

SIR_(estimated) is calculated as follows.

(1) Radio quality information of the shared channel is calculated basedon radio quality of the uplink reference signal, a target receptionlevel of the shared channel, and an uplink interference level.

(2) A first offset process is performed for radio quality information ofthe shared channel based on the decoding result of the Uplink SharedChannel and the required uplink quality.

(3) A second offset process is performed for radio quality informationof the shared channel based on the priority level determined by the datatype. Radio quality information of the shared channel after the firstoffset process and the second offset process corresponds toSIR_(estimated).

Specifically, the base station apparatus (eNB) calculates a transmissionpower offset value Δ_(i,data) ^(eNB)) for the PUSCH relative to theSounding RS, according to the following equation (Δ_(i,data) ^((eNB)) isa offset value in terms of a power value per one RB). UPH (UE PowerHeadroom) of UE #i is defined as UPH_(i), the transmission bandwidth ofthe Sounding Reference Signal is defined as B_(i,ref), and thetransmission bandwidth of the PUSCH is defined as B_(i,data).

The term of min (,) in the equation (6) ([Equation 7]) is applied whenB_(i,ref)=1 (RB) (180 kHz).

$\begin{matrix}\left\lbrack {{Equation}\mspace{14mu} 7} \right\rbrack & \; \\{\Delta_{i,{data}}^{({eNB})} = {\min \begin{pmatrix}{{{Target}_{i,{RoT}} - {SRSP}_{i}},} \\{{UPH}_{i} + {10 \cdot {\log_{10}\left( \frac{B_{i,{ref}}}{B_{i,{data}}} \right)}}}\end{pmatrix}}} & (6)\end{matrix}$

where SRSP_(i) denotes the reception level of the Sounding ReferenceSignal. Further, B_(i,ref) denotes the bandwidth in which the SoundingReference Signal is transmitted, and B_(i,data) denotes the bandwidth inwhich the PUSCH is transmitted. B_(i,data) corresponds to the bandwidthfor the Temporary RB group. Target_(i,RoT) is calculated based onPathloss and Table 4. As Pathloss_(i), a value calculated based on theUPH may be used. Alternatively, as Pathloss_(i), a value of Pathlossreported as the Measurement report by the user equipment terminal (UE)may be used. When the value calculated based on the UPH is used asPathloss_(i), Pathloss_(i) is calculated according to the followingequation.

Pathloss=P _(max) −UPH−SRSP(in dB) (in consideration of the band)

where P_(max) denotes rated power (24 dBm) of the user equipmentterminal (UE).

UPH=(rated power of UE)−(transmission power of the Sounding ReferenceSignal)

This equation is calculated in the units of dB.

TABLE 4 Relationship between Target_(ROT) and Pathloss Target_(ROT) (dB)Pathloss (dB) Y₀ 0~X₁ Y₁ X₁~X₂ Y₂ X₂~X₃ Y₃ X₃~X₄ Y₄ X₄~X₅ Y₅ X₅~X₆ Y₆X₆~X₇ Y₇ X₇~

Next, the base station apparatus (eNB) calculates the estimated SIR(SIR_(i,estimated)) of the UL-SCH according to the following equation(7) ([Equation 8]).

[Equation 8]

SIR _(i,estimated) =SRSP _(i)+Δ_(i,data) ^((eNB))−Interference  (7)

where SRSP_(i) denotes the reception level of the Sounding ReferenceSignal. “Interference” corresponds to the uplink interference level.

In addition, the base station apparatus (eNB) adjusts the value ofSIR_(i,estimated) based on the following equation (8) ([Equation 9]),when the function for adjusting SIR_(estimated) is “On”. The calculationof SIR_offset_(i) will be described below.

[Equation 9]

SIR _(i,estimated) =SIR _(i,estimated) +SIR_offset_(i)  (8)

Transmission power information Δ_(data) to be reported to the userequipment terminal (UE) by means of the UL Scheduling Grant via thePhysical Downlink Control Channel is calculated as follows. Thistransmission power information Δ_(data) corresponds to the power offsetfor the PUSCH relative to the Sounding Reference Signal.

$\begin{matrix}\left\lbrack {{Equation}\mspace{14mu} 10} \right\rbrack & \; \\{\Delta_{data} = {\Delta_{data}^{({eNB})} + {{10 \cdot \log}\mspace{14mu} 10\left( \frac{B_{data}}{B_{ref}} \right)}}} & (9)\end{matrix}$

[Process Performed in the Long Interval]

SIR_offset_(i) is adjusted in an outer-loop manner based on the CRCresult of the UL-SCH for the user equipment terminal (UE) #i, accordingto the following equation. SIR_offset_(i) is adjusted in the outer-loopmanner based on the CRC result of the UL-SCH in which the priority levelof the logical channel group with the highest priority level isZ_(i,adjust) (equation (10) ([Equation 11])). When the priority level ofthe logical channel group with the highest priority level is differentfrom Z_(i,adjust), SIR_offset_(i) is not adjusted in the outer-loopmanner.

Since the base station apparatus (eNB) cannot identify the logicalchannel included in the MAC PDU until the CRC result is OK, the prioritylevel of the logical channel group with the highest priority leveldetermined in Section 4.1.10 (Scheduling Coefficient Calculation) isused as the “priority level of the logical channel group with thehighest priority level” in this process.

SIR_offset_(i) is adjusted for each user equipment terminal (UE). Thepriority level Z_(i,adjust) in this process is adjusted via the MT(maintenance tool or external interface) for each user equipmentterminal (UE).

It should be noted that Δ_(adj) ^((P)) and BLER_(target) ^((P)) can bedesignated via the external input interface (I/F). The maximum value ofSIR_offset_(i) is defined as SIR_offset_(p) ^((max)) and the minimumvalue of SIR_offset_(i) is defined as SIR_offset_(p) ^((min)). WhenSIR_offset_(i) is continuously determined as the maximum value or theminimum value, the following calculation is not performed.

$\begin{matrix}\left\lbrack {{Equation}\mspace{14mu} 11} \right\rbrack & \; \\{{SIR\_ offset}_{i} = \left\{ \begin{matrix}\begin{matrix}{{SIR\_ offset}_{i} + {\Delta_{adj}^{({Pz})} \times}} \\{BLER}_{target}^{({Pz})}\end{matrix} & {{Input} = {\,{``{Ack}"}}} \\\begin{matrix}{{SIR\_ offset}_{i} - {\Delta_{adj}^{({Pz})} \times}} \\\left( {1 - {BLER}_{target}^{({Pz})}} \right)\end{matrix} & {{Input} = {\,{``{Nack}"}}} \\{SIR\_ offset}_{i} & {{Input} = {\,{``{DTX}"}}}\end{matrix} \right.} & (10)\end{matrix}$

[Process of Determining RBs, the Data Size, and the Modulation Scheme]

(1) In the case where the user equipment terminal (UE) transmits theUL-SCH for initial transmission in the corresponding sub-frame;

(Correction Process of the Allocation Bandwidth Based on UPH)

The bandwidth for the Temporary RB group is defined as B_(i,data,tmp).

If Target_(i,RoT)−SRSP_(i)>UPH_(i)+10*log₁₀ (B_(i,ref)/B_(i,data,tmp)),then it is assumed as follows.

$\begin{matrix}\left\lbrack {{Equation}\mspace{14mu} 12} \right\rbrack & \; \\{B_{i,{data}} = \frac{B_{i,{ref}}}{10^{\frac{{Target}_{i,{RoT}} - {SRSP}_{i} - {UPH}_{i}}{10}}}} & \;\end{matrix}$

Also, the number of RBs included in B_(i,data) is defined as the numberof RBs Num_(RB) to be allocated. Then, RBs in the Temporary RB group areremoved, such that the number of RBs to be allocated to the userequipment terminal (UE) is not less than Num_(RB), and the number ofsubcarriers includes only factors of 2, 3, and 5.

Upon allocation of the Temporary RB group, when RBs are allocatedbeginning from the highest frequency, RBs are removed beginning from thelowest frequency. On the other hand, when RBs are allocated beginningfrom the lowest frequency, RBs are removed beginning from the highestfrequency.

Namely, when transmission power of the user equipment terminal (UE PowerHeadroom reported from the user equipment terminal) is less than apredetermined threshold, frequency resources to be allocated to theshared channel are decreased.

If Target_(i,RoT)−SRSP_(i)=<UPH_(i)+10*log₁₀ (B_(i,ref)/B_(i,data,tmp)),then it is assumed as follows.

Num_(RB)=N_(allocated)

(Offset Process Based on the Priority Level of the Logical ChannelGroup)

The SIR (SIR_(estimated) ^((RB))) is adjusted by the offset based on thepriority level of the logical channel group with the highest prioritylevel. Δ_(LCG) is designated via the external interface (I/F). Thesubscript LCG refers to the logical channel group.

SIR _(estimated) ^((RB)) =SIR _(estimated) ^((RB))−Δ_(LCG)

(Calculation for Transport Format)

With reference to the UL_TF_related_table using the number of RBs(RB_available) in the Temporary RB group and SIR_(estimated) ^((RB)) asarguments, a MAC PDU size (hereinafter described as Size) and amodulation scheme (hereinafter described as Modulation) are determined.

Size=UL_Table_TF_SIZE (RB_available, SIR_(estimated) ^((RB)))

Modulation=UL_Table_TF_Mod (RB_available, SIR_(estimated) ^((RB)))

If Size>N_(max,bit), then the value of SIR_(estimated) ^((RB)) isdecremented by 1 (dB) until Size=<N_(max,bit). (A smaller SIR isreferred in the UL_TF_related_table. In this case, the value ofRB_available is fixed.) After Size is determined, Modulation is adjustedto the corresponding value in the UL_TF_related_table.

Next, the number of RBs to be allocated to the user equipment terminal(UE) is recalculated based on the comparison between the amount of datain the UL Buffer and the Size. Please refer to Section 4.1.10.2 for theamount of data in the UL Buffer. α_(ULTFRS) is a coefficient designatedvia the external interface (I/F). For example, α_(ULTFRS) is set to be1.0 or 2.0.

When the base station apparatus receives from the user equipmentterminal (UE) “allocation request for the PUSCH: REQUESTING” by means ofthe Scheduling request and uplink resources (PUSCH) have not beenallocated to the user equipment terminal (UE) since the base stationapparatus has received the Scheduling request, the following process “inthe case of Size=<α_(ULTFRS)*(Buffer_(j,h) ^((UL))+Buffer_(j,l) ^((UL))”is performed.

<In the Case of Size=<α_(ULTFRS)*(Buffer_(j,h) ^((UL))+Buffer_(j,l)^((UL))>

The base station apparatus determines that there are enough data in theUE buffer and all the RBs in the Temporary RB group are to be allocatedto the user equipment terminal (UE).

<In the Case of Size>α_(ULTFRS)*(Buffer_(j,h) ^((UL))+Buffer_(j,l)^(UL))>

The base station apparatus determines that there are not enough data inthe UE buffer and the number of RBs Num_(RB) to be allocated isrecalculated with reference to the UL_TF_related_table usingα_(ULTFRS)*(Buffer_(j,h) ^((UL))+Buffer_(j,l) ^((UL)) (hereinafterdescribed as Size_(buffer)) and SIR_(estimated) ^((RB)) as arguments.

Num_(RB)=UL_Table_TF_RB (Size_(buffer), SIR_(estimated) ^((RB)))

Size=UL_Table_TF_SIZE (Num_(RB), SIR_(estimated) ^((RB)))

Modulation=UL_Table_TF_Mod (Num_(RB), SIR_(estimated) ^((RB)))

When the number of subcarriers corresponding to Num_(RB) includesfactors other than 2, 3, and 5, Num_(RB) is determined as a minimuminteger among integers which include only factors of 2, 3, and 5 for thenumber of subcarriers and which are greater than Num_(RB).

RBs in the Temporary RB group are removed, such that the number of RBsto be allocated to the user equipment terminal (UE) is not less thanNum_(RB). Upon allocation of the Temporary RB group, when RBs areallocated beginning from the highest frequency, RBs are removedbeginning from the lowest frequency. On the other hand, when RBs areallocated beginning from the lowest frequency, RBs are removed beginningfrom the highest frequency.

Namely, when the amount of data in the buffer of the user equipmentterminal is less than the data size determined as the transmissionscheme, the amount of frequency resources (the number of RBs) determinedas the transmission scheme is decreased.

(2) In the case where the user equipment terminal transmits the UL-SCHfor retransmission in the corresponding sub-frame;

Transmission power information Δ_(data) to be reported to the userequipment terminal (UE) is adjusted based on the following equation,when the Uplink Scheduling Grant is specified via the Physical UplinkControl Channel for retransmission. Δ_(data) ^((eNB)) and 10*log₁₀(B_(data)/B_(ref)) are calculated at the retransmission timing. Anoffset value Δ_(LCG) ^((HARQ)) is designated via the external interface(I/F) for each logical channel group.

$\begin{matrix}\left\lbrack {{Equation}\mspace{14mu} 13} \right\rbrack & \; \\{\Delta_{data} = {\Delta_{data}^{({eNB})} + {10 \cdot {\log_{10}\left( \frac{B_{data}}{B_{ref}} \right)}} + \Delta_{LCG}^{({HARQ})}}} & \;\end{matrix}$

Namely, the base station apparatus calculates transmission power of theshared channel based on the reception level of the uplink referencesignal and the target reception level of the shared channel, and thenperforms the offset process for transmission power of the shared channelbased on whether data are to be initially transmitted or to beretransmitted via the shared channel.

In step S416, the value of “j” is incremented by one. In step S418, itis determined whether the value of “j” is less than or equal toN_(UL-SCH). If the value of “j” is less than or equal to N_(UL-SCH)(step S418: YES), the process returns to step S410. Otherwise (stepS418: NO), the process comes to an end.

Next, the base station apparatus 200 according to an embodiment of thepresent invention is described with reference to FIG. 6.

As shown in FIG. 6, the base station apparatus 200 according to anembodiment of the present invention includes a scheduling coefficientcalculation unit 206 (as a selection unit), a transport format andresource block selection unit 210 (as an allocation unit), and a layer 1processing unit 212.

The scheduling coefficient calculation unit 206 performs the process ofstep S204.

Specifically, the scheduling coefficient calculation unit 206 selectsuser equipment terminals (UEs) to which radio resources are to beallocated according to dynamic scheduling in the corresponding sub-frameand supplies the number of user equipment terminals (UEs) N_(UL-SCH) towhich radio resources are to be allocated according to dynamicscheduling to the transport format and resource block selection unit210.

The transport format and resource block selection unit 210 performs theprocess of step S208. Specifically, the transport format and resourceblock selection unit 210 performs uplink transport format and resourceselection. More specifically, the transport format and resource blockselection unit 210 reserves radio resources (RBs) for the PhysicalRandom Access Channel (PRACH), reserves prohibited radio resources (RBs)or guard RBs, reserves radio resources (RBs) for the UL-SCH to whichpersistent scheduling is to be applied, and then determines atransmission format for the UL-SCH to which dynamic scheduling is to beapplied and allocates radio resources for the UL-SCH to which dynamicscheduling is to be applied (including for both initial transmission andretransmission).

The layer 1 processing unit 212 performs a process related to the layer1.

Second Embodiment

Next, a best mode for carrying out the present invention is describedbased on a second embodiment described below with reference to theaccompanying drawings.

Throughout the figures for illustrating the embodiments of the presentinvention, the same reference numerals are used for the same orequivalent elements and their repeated descriptions may be omitted.

First, a radio communication system having a base station apparatusaccording to an embodiment of the present invention is described withreference to FIG. 1.

As shown in FIG. 1, the radio communication system 1000, which may be anEvolved UTRA (Universal Terrestrial Radio Access) and UTRAN (UTRANetwork) system (a.k.a an LTE (Long Term Evolution) system or a super 3Gsystem), includes a base station apparatus (eNB: eNode B) 200 and pluralsets of user equipment (UE) 100 _(n) (100 ₁, 100 ₂, 100 ₃, . . . 100_(n); n: an integer greater than zero (0)) (hereinafter, the userequipment (UE) may be referred to as a user equipment terminal(s)). Thebase station apparatus 200 is connected to an upper node such as anaccess gateway apparatus 300. The access gateway apparatus 300 isconnected to a core network 400. In this case, the user equipmentterminals 100 _(n) are in communication with the base station apparatus200 in a cell 50 based on the Evolved UTRA and UTRAN radio communicationscheme.

Each of the user equipment terminals (100 ₁, 100 ₂, 100 ₃, . . . 100_(n)) has the same configuration, functions, and status. Therefore,unless otherwise described, the term of user equipment terminals (UE)100 _(n) may be collectively used in the following descriptions.

As the radio access scheme in the radio communication system 1000, theOFDM (Orthogonal Frequency Division Multiplexing) scheme and the SC-FDMA(Single-Carrier Frequency Division Multiplexing Access) scheme are usedin downlink and uplink communications, respectively. As described above,the OFDM scheme is a multi-carrier transmission scheme in which afrequency band is divided into plural sub-carriers having narrowfrequency bands and data are mapped on each sub-carrier to betransmitted. The SC-FDMA scheme is a single-carrier transmission schemein which a frequency band is divided so that different frequencies canbe used among plural terminals and as a result, interference betweenterminals can be reduced.

Next, communication channels used in the Evolved UTRA and UTRAN radiocommunication scheme are described.

In downlink communications, a Physical Downlink Shared Channel (PDSCH)shared among the user equipment terminals 100 _(n) and a PhysicalDownlink Control Channel (PDCCH) are used. The Physical Downlink ControlChannel (PDCCH) may also be called a DL L1/L2 Control Channel. Indownlink, transport format information and user information of the userto which the Physical Downlink Shared Channel is transmitted, transportformat information and user information of the user by which a PhysicalUplink Shared Channel (PUSCH) is transmitted, acknowledge information ofthe PUSCH (or an Uplink Shared Channel (UL-SCH) as a transport channel),and the like are reported via the Physical Downlink Control Channel(PDCCH). User data are transmitted via the Physical Downlink SharedChannel. The user data are transmitted via a Downlink Shared Channel(DL-SCH) as a transport channel. The transport format information anduser information of the user to which Physical Downlink Shared Channelis transmitted, which are transmitted via the Physical Downlink ControlChannel (PDCCH), are called Downlink Scheduling Information. Thetransport format information and user information of the user by whichthe Physical Uplink Shared Channel (PUSCH) is transmitted, which aretransmitted via the Physical Downlink Control Channel (PDCCH), arecalled an Uplink Scheduling Grant.

In uplink communication, the Physical Uplink Shared Channel (PUSCH) thatis shared among user equipment terminals 100 _(n) and an LTE controlchannel are used. The LTE control channel has two types; one is to betime-multiplexed with the Physical Uplink Shared Channel (PUSCH) and theother is to be frequency-multiplexed with the Physical Uplink SharedChannel (PUSCH). The control channel to be frequency-multiplexed withthe Physical Uplink Shared Channel (PUSCH) is called a Physical UplinkControl Channel (PUCCH).

In uplink communication, a downlink Channel Quality Indicator (CQI) tobe used for scheduling for the Downlink Shared Channel (DL-SCH) andAdaptive Modulation and Coding (AMC), and acknowledgement information ofthe Downlink Shared Channel (HARQ ACK information) are transmitted viathe LTE control channel. Further, user data are transmitted via thePhysical Uplink Shared Channel (PUSCH). The user data are transmittedvia an Uplink Shared Channel (UL-SCH) as a transport channel.

1. Uplink MAC Communication Control Procedure

Next, an uplink MAC (UL MAC) communication control procedure as acommunication control method performed in a base station apparatusaccording the present embodiment is described.

In this embodiment, a logical channel corresponds to, for example, aRadio bearer; and a priority class corresponds to, for example, apriority level (or priority) or logical channel priority. In thisembodiment, logical channels can be classified into four logical channelgroups. The correspondence between the logical channel and the logicalchannel group can be arbitrarily determined.

Unless otherwise described, the “corresponding sub-frame” refers to asub-frame in which the user equipment terminal transmits the UplinkShared Channel (UL-SCH) according to scheduling.

In the following descriptions, dynamic scheduling corresponds to a firstresource allocating scheme for dynamically allocating radio resources.When dynamic scheduling is applied to the Uplink Shared Channel(UL-SCH), radio resources are allocated to the user equipment terminalin arbitrary sub-frames. Further, in this case, various values may beset as the values of the transmission format including allocationinformation about resource blocks (frequency resources), a modulationscheme, a payload size, information about transmission power, HARQinformation (a Redundancy version parameter, a process number, etc.),and MIMO information (a reference signal sequence for MIMO transmission,etc.). The transmission format including allocation information aboutresource blocks (frequency resources), a modulation scheme, a payloadsize, information about transmission power, HARQ information (aRedundancy version parameter, a process number, etc.), and MIMOinformation (a reference signal sequence for MIMO transmission, etc.) isreported to the user equipment terminal (UE) by means of the ULScheduling Grant to be mapped to the Physical Downlink Control Channel(PDCCH).

On the other hand, persistent scheduling is a scheduling scheme forperiodically allocating data transmission opportunities in accordancewith a data type or features of the application to transmit/receivedata. Persistent scheduling corresponds to a second resource allocatingscheme for periodically allocating radio resources. Namely, whenpersistent scheduling is applied to the Uplink Shared Channel (UL-SCH),radio resources are allocated to the user equipment terminal inpredetermined sub-frames. Further, in this case, predetermined valuesare set as the values of the transmission format including allocationinformation about resource blocks (frequency resources), a modulationscheme, a payload size, information about transmission power, HARQinformation (a Redundancy version parameter, a process number, etc.),and MIMO information (a reference signal sequence for MIMO transmission,etc.). Namely, radio resources are allocated in the predeterminedsub-frames, and the Uplink Shared Channel (UL-SCH) is transmitted usingthe predetermined transmission format. In this case, the predeterminedsub-frames may be arranged, for example, at a predetermined cycle.Further, the predetermined transmission format is not necessarily fixedto one type, so that plural types of transmission formats may beprovided.

2. Allocation Unit of the Transmission Band for the Physical UplinkShared Channel (PUSCH)

In the present embodiment, the transmission band in the frequencydirection is allocated in terms of resource blocks (RBs). For example,one resource block (1 RB) corresponds to 180 kHz. The number of RBs isequal to 25 for the system bandwidth of 5 MHz, is equal to 50 for thesystem bandwidth of 10 MHz, and is equal to 100 for the system bandwidthof 20 MHz. Also, the transmission band for the PUSCH is allocated interms of RBs in each sub-frame. In addition, RBs are allocated such thatfactors of the DFT size do not include values other than 2, 3, and 5. Inother words, the factors of the DFT size only include 2, 3, and 5.

For retransmission of the Uplink Shared Channel (UL-SCH), the basestation apparatus 200 may or may not transmit the corresponding UplinkScheduling Grant. For example, when the Uplink Scheduling Grant forretransmission of the Uplink Shared Channel (UL-SCH) can be transmitted,the base station apparatus 200 may transmit the Uplink Scheduling Grant.The “Uplink Scheduling Grant for retransmission of the Uplink SharedChannel (UL-SCH) can be transmitted” may mean that there are radioresources (i.e., frequency resources, time resources, or powerresources) available for transmitting the Uplink Scheduling Grant. Whenthe base station apparatus 200 transmits the Uplink Scheduling Grant forretransmission of the Uplink Shared Channel (UL-SCH), the user equipmentterminal retransmits the Uplink Shared Channel (UL-SCH) according to theUplink Scheduling Grant. As described above, the Uplink Scheduling Grantincludes the identification information of the user equipment terminalwhich communicates using the shared channel in the correspondingsub-frame and also includes the transmission format of the sharedchannel such as allocation information about resource blocks (frequencyresources), a modulation scheme, a payload size, information abouttransmission power, HARQ information (a Redundancy version parameter, aprocess number, etc.), and MIMO information (a reference signal sequencefor MIMO transmission, etc.).

It should be noted that only a portion of the Uplink Scheduling Grantmay be modified from the corresponding portion for initial transmission.For example, only allocation information about resource blocks(frequency resources) and information about transmission power may bemodified.

As used herein, dynamic scheduling corresponds to a first resourceallocating scheme for dynamically allocating radio resources.

When the base station apparatus 200 transmits the Uplink SchedulingGrant for retransmission of the Uplink Shared Channel (UL-SCH), the basestation apparatus 200 may concurrently transmit the ACK via a PhysicalHybrid ARQ Indicator Channel (PHICH). The effect of transmitting the ACKvia the PHICH upon transmitting the Uplink Scheduling Grant forretransmission of the Uplink Shared Channel (UL-SCH) is described below.When the user equipment terminal (UE) cannot successfully receive theUplink Scheduling Grant for retransmission of the Uplink Shared Channel(UL-SCH), the user equipment terminal follows information (i.e.,ACK/NACK) transmitted via the PHICH. When the information transmittedvia the PHICH is the ACK, the user equipment terminal (UE) stopsretransmission of the UL-SCH. Otherwise (in the case of the NACK), theuser equipment terminal (UE) retransmits the UL-SCH using the samefrequency resources as the resources used for previous transmission. Inthis case, when the frequency resources used for previous transmissionare different from the frequency resources specified by the ULScheduling Grant and when the base station apparatus instructs anotheruser equipment terminal (UE) to transmit the UL-SCH with thecorresponding frequency resources used for the previous transmission,the Uplink Shared Channel (UL-SCH) for retransmission by the userequipment terminal (UE) collides with the Uplink Shared Channel (UL-SCH)for transmission by the other user equipment terminal (UE). As a result,transmission properties are degraded. When the base station apparatus200 transmits the ACK via the PHICH upon transmitting the UplinkScheduling Grant for retransmission of the Uplink Shared Channel(UL-SCH), degradation of transmission properties can be avoided. Theprocess of transmitting the ACK via the PHICH upon transmitting theUplink Scheduling Grant for retransmission of the Uplink Shared Channel(UL-SCH) also applies to the process of transmitting the ACK via thePHICH upon transmitting the Uplink Scheduling Grant for initialtransmission of the Uplink Shared Channel (UL-SCH).

As described above, adequately transmitting the UL Scheduling Grant andthe PHICH allows for more reliable communications using the controlchannel. As a result, transmission properties can be improved. FIG. 7Ashows a flowchart of a method of transmitting the UL Scheduling Grantand the PHICH. With reference to FIG. 7, the method of transmitting theUL Scheduling Grant and the PHICH is described.

In step S902, the base station apparatus determines whether the UL-SCHis to be retransmitted in the corresponding sub-frame. When the UL-SCHis to be retransmitted in the corresponding sub-frame (step S902: YES),the base station apparatus determines whether there is an available ULScheduling Grant to be transmitted in step S904. When there is anavailable UL Scheduling Grant to be transmitted (step S904: YES), theprocess goes to step S906. On the other hand, when there is no availableUL Scheduling Grant to be transmitted (step S904: NO), the process goesto step S910. The “available UL Scheduling Grant to be transmitted”means that the Uplink Scheduling Grant can be transmitted to the userequipment terminal (UE). For example, it may also mean that there areradio resources (i.e., frequency resources, time resources, or powerresources) available for transmitting the Uplink Scheduling Grant.

Next, in step S906, the base station apparatus determines whether RBRemaining Check, which will be described below with reference to stepS810 in FIG. 8, is OK. When the RB Remaining Check in step S810 is OK(step S906: YES), the process goes to step S908. On the other hand, whenthe RB Remaining Check in step S810 is NG (step S906: NO), the processgoes to step S910.

Next, in step S908, the base station apparatus determines that the ULScheduling Grant for retransmission and the PHICH (ACK) are to betransmitted. The PHICH (ACK) is used to temporarily stop retransmissionof the UL-SCH, when the UL Scheduling Grant is not detected by the userequipment terminal (UE) (missed detection). In step S910, the basestation apparatus determines that PHICH (ACK) is to be transmitted. ThisPHICH (ACK) temporarily stops retransmission of the UL-SCH.

When the UL-SCH is not to be retransmitted in the correspondingsub-frame (step S902: NO), the base station apparatus determines whetherthe PHICH (ACK) is to be transmitted in step S912. The “PHICH (ACK) isto be transmitted” means that the user equipment terminal (UE)transmitted the UL-SCH at the immediately preceding HARQ transmissiontiming (i.e., at the transmission timing before one HARQ RTT) and theUL-SCH was successfully decoded (i.e., the CRC result was OK). When thePHICH (ACK) is to be transmitted, that is, when the CRC result of theUL-SCH transmitted before one HARQ RTT was OK (step S912: YES), theprocess goes to step S914.

In step S914, the base station apparatus determines whether the ULScheduling Grant for initial transmission in the corresponding sub-frameis to be transmitted. When the UL Scheduling Grant for initialtransmission in the corresponding sub-frame is to be transmitted (stepS914: YES), the process goes to step S916. When the UL Scheduling Grantfor initial transmission in the corresponding sub-frame is not to betransmitted (step S914: NO), the process goes to step S918.

In step S916, the base station apparatus determines that the ULScheduling Grant for initial transmission and the PHICH (ACK) are to betransmitted. As described above, the PHICH (ACK) is used to temporarilystop retransmission of the UL-SCH, when the UL Scheduling Grant is notdetected by the user equipment terminal (UE) (missed detection). In stepS918, the base station apparatus determines that the PHICH (ACK) is tobe transmitted.

On the other hand, when the PHICH (ACK) is not to be transmitted, thatis, when the CRC result of the UL-SCH transmitted before one HARQ RTTwas not OK (step S912: NO), the process goes to step S920. The “PHICH(ACK) is not to be transmitted” means that the user equipment terminal(UE) did not transmit the UL-SCH before one HARQ RTT.

In step S920, the base station apparatus determines whether the ULScheduling Grant for initial transmission in the corresponding sub-frameis to be transmitted. When the base station apparatus determines thatthe UL Scheduling Grant for initial transmission in the correspondingsub-frame is to be transmitted (step S920: YES), the process goes tostep S922. In step S922, the base station apparatus determines that theUL Scheduling Grant for initial transmission in the correspondingsub-frame is to be transmitted. On the other hand, when the base stationapparatus determines that the UL Scheduling Grant for initialtransmission in the corresponding sub-frame is not to be transmitted(step S920: NO), the base station apparatus determines that the PHICHand the UL Scheduling Grant are not to be transmitted.

3. UL MAC Data Transmission Procedure

Next, an uplink MAC (UL MAC) data transmission procedure is describedwith reference to FIG. 2. FIG. 2 shows a procedure, starting from ascheduling process of calculating scheduling coefficients, to an UL TFRselection process of determining the transport format and RBs to beallocated.

3.1. Setting of UL MAC Maximum Multiplexing Number N_(ULMAX)

In step S202, an UL MAC maximum multiplexing number N_(ULMAX) is set inthe base station apparatus 200. The UL MAC maximum multiplexing numberN_(ULMAX) is the maximum multiplexing number in one sub-frame of theUplink Shared Channel (UL-SCH) (including both the UL-SCH for initialtransmission and the UL-SCH for retransmission) to which dynamicscheduling is applied and is designated via the external input interface(I/F). The “UL MAC maximum multiplexing number is designated via theexternal input interface” means that the UL MAC maximum multiplexingnumber is specified by an upper node or another node in the core networkor is set as an internal parameter, for example.

3.2. Calculation for Scheduling Coefficients

Next, in step S204, Calculation for Scheduling coefficients is performedin the base station apparatus 200. The user equipment terminals (UEs) towhich radio resources are to be allocated according to dynamicscheduling in the corresponding sub-frame are selected. Then, UplinkTransport format and Resource selection is performed, as describedbelow, with respect to the user equipment terminals (UEs) to which radioresources are to be allocated according to dynamic scheduling in thecorresponding sub-frame. The “user equipment terminals (UEs) to whichradio resources are to be allocated according to dynamic scheduling”include both a user equipment terminal (UE) having retransmission datato be transmitted in the corresponding sub-frame and a user equipmentterminal (UE) having data to be initially transmitted which are selectedbased on Calculation for Scheduling Coefficients.

The number of user equipment terminals (UEs) to which radio resourcesare to be allocated according to dynamic scheduling in the correspondingsub-frame is defined as N_(UL-SCH).

3.4. Uplink Transport Format and Resource Selection (UL TFR Selection)

Next, in step S208, Uplink Transport format and Resource selection isperformed in the base station apparatus 200. The base station apparatus200 reserves radio resources (RBs) for the Physical Random AccessChannel (PRACH), reserves prohibited radio resources (RBs) or guard RBs,reserves radio resources (RBs) for the UL-SCH to which persistentscheduling is applied, and then determines a transmission format for theUL-SCH to which dynamic scheduling is applied and allocates radioresources for the UL-SCH to which dynamic scheduling is applied(including for both initial transmission and retransmission). It shouldbe noted that Uplink Transport format and Resource selection includesuplink transmission power control.

4. Calculation for Scheduling Coefficients

Next, Calculation for Scheduling coefficients performed in step S204 isdescribed with reference to FIG. 7B.

4.1. Process Flow

FIG. 7B shows a process of selecting candidates for the user equipmentterminals (UEs) to which radio resources are to be allocated accordingto dynamic scheduling, by calculating the scheduling coefficients. Thebase station apparatus 200 performs the following processes with respectto all the user equipment terminals (UEs) in an LTE active state (in anRRC (Radio Resource Control) connected state).

As shown in FIG. 7B, in step S701, equations of n=1, N_(Scheduling)=0,N_(Retransmission)=0 are provided; where n denotes an index of the userequipment terminals 100 _(n) and n=1, . . . , N (N is an integer greaterthan 0).

Next, in step S702, Renewal of HARQ (Hybrid Automatic Repeat reQuest)Entity Status is performed. In this step, with respect to the userequipment terminal (UE), a process in which the CRC result of the UL-SCHis OK is released.

Further, a process in which the maximum number of retransmission timeshas been reached is also released and the user data in the process arediscarded. As used herein, the maximum number of retransmission times isindependently determined for each user equipment terminal (UE).

Further, a process in which no transmission of the UL-SCH is detectedupon power detection of the Uplink Shared Channel is also released.

Next, persistent scheduling is performed. Persistent scheduling is ascheduling scheme for periodically allocating data transmissionopportunities in accordance with a data type or features of theapplication to transmit/receive data. Further, the data type may includedata of Voice Over IP, Streaming data or the like. The Voice Over IP orthe Streaming corresponds to the application.

Regarding resource allocation according to persistent scheduling inuplink, in the case where data are generated, i.e., in the case oftransition from a silence period to a talk spurt, persistent resourcesare allocated at the timing when the Scheduling Request and the BufferStatus Report are transmitted. In the case of transition from the talkspurt to the silence period, persistent resources are released when anEmpty Buffer Status Report is transmitted from the user equipmentterminal (UE) to the base station apparatus. The Empty Buffer StatusReport refers to a signal indicating that the amount of data in thebuffer is equal to zero (0). The persistent resources refer to radioresources, specifically frequency resources, which are allocatedaccording to persistent scheduling.

The base station apparatus 200 determines whether persistent resourcesare to be allocated to the user equipment terminal (UE) in thecorresponding sub-frame. When persistent resources are to be allocated,the base station apparatus 200 also determines whether data are to beinitially transmitted or to be retransmitted in step S703.

When it is determined in step S703 that persistent resources are to beallocated and data are to be retransmitted, N_(Retrans,persist) isincremented by one (N_(Retrans,persist)++) in step S704, and then theuser equipment terminal (UE) is excluded from a target of the schedulingprocess for initial transmission. When the user equipment terminal (UE)is excluded from a target of the scheduling process for initialtransmission, the scheduling coefficients are not calculated in stepS732, and as a result, the scheduling process for initial transmissionis not performed.

When it is determined in step S703 that persistent resources are to beallocated and data are to be initially transmitted, the persistentresources are reserved in step S705.

Then, the process goes to step S728 in which Low/High Fd Check isperformed. In this case, with regard to the user equipment terminal (UE)for which the persistent resources are reserved in step S705, BufferStatus Check in step S730 and Scheduling Coefficient Calculation in stepS732 are performed. When transmission resources are allocated accordingto dynamic scheduling in the corresponding sub-frame, the user equipmentterminal (UE) transmits the MAC PDU (UL-SCH) based on the transmissionresources allocated according to dynamic scheduling. Even when thetransmission resources are allocated according to dynamic scheduling,persistent resources are reserved. In other words, even when thetransmission resources are allocated according to dynamic scheduling,persistent resources are not released.

Since whether persistent resources are to be allocated in thecorresponding sub-frame is determined in step S703 before HARQRetransmission Check in step S706, initial transmission according topersistent scheduling has precedence over retransmission according todynamic scheduling. When retransmission according to dynamic schedulingis not performed due to initial transmission according to persistentscheduling, the ACK is transmitted as acknowledge information for theshared channel to which dynamic scheduling is applied for thisretransmission. Transmitting the ACK allows transmission of the sharedchannel to which dynamic scheduling is applied to be absolutely stopped.

When persistent resources are not to be allocated, the process goes toHARQ Retransmission Check in step S706.

Next, in step S706, HARQ Retransmission Check is performed. It isdetermined whether the user equipment terminal (UE) has data to beretransmitted in the corresponding sub-frame. The “data to beretransmitted” refer to retransmission data which satisfy the followingfour conditions:

-   -   the timing of retransmitting data corresponds to the        retransmission timing according to Synchronous HARQ, and the        NACK or the UL Scheduling Grant for transmission of the UL-SCH        in the corresponding sub-frame is transmitted to the user        equipment terminal (UE);    -   the previous CRC results of the UL-SCH are not OK;    -   the maximum number of retransmission times has not been reached;        and    -   “no transmission of the UL-SCH” is not detected upon power        detection of the Uplink Shared Channel.

When the user equipment terminal (UE) has data to be retransmitted, theprocess of the HARQ Retransmission Check returns “Retransmission”.Otherwise, the process of the HARQ Retransmission Check returns “Noretransmission”. When the result of the HARQ Retransmission Check isdetermined as “No retransmission”, the process goes to step S710 inwhich Measurement Gap Check is performed.

With regard to the user equipment terminal which has transmitted the ACK(HARQ Process), when the maximum number of retransmission times has notbeen reached, it is assumed that the user equipment terminal (UE) has“data to be retransmitted” in the next transmission timing according toSynchronous HARQ. Specifically, when the results in step S902 and stepS904 are determined as NO and when the PHICH (ACK) is transmitted instep S910 in spite of the fact that the previous CRC result of thecorresponding data (UL-SCH) is not OK, it is assumed that the userequipment terminal (UE) has “data to be retransmitted” in the nexttransmission timing according to Synchronous HARQ. In this case, thePHICH (ACK) does not mean that the CRC result is OK, but means thatretransmission of the UL-SCH is temporarily stopped.

When the result of the HARQ Retransmission Check is determined as“Retransmission”, N_(Retransmission) is incremented by one in step S708(N_(Retransmission)++), and then the user equipment terminal (UE) isexcluded from a target of the scheduling process for initialtransmission. When the user equipment terminal (UE) is excluded from atarget of the scheduling process for initial transmission, thescheduling coefficients are not calculated in step S732, and as aresult, the scheduling process for initial transmission is notperformed.

Next, in step S710, Measurement Gap Check is performed. In this step,the base station apparatus 200 does not allocate the Uplink SharedChannel (RBs for the Uplink Shared Channel) to the user equipmentterminal (UE), when the time interval during which the user equipmentterminal (UE) measures a cell with a different frequency overlaps a timeframe in which the Physical Downlink Control Channel for the UplinkShared Channel is transmitted in downlink, a time frame in which theshared channel is received, or a time frame in which acknowledgeinformation for the Uplink Shared Channel is transmitted. The ULScheduling Grant for the Uplink Shared Channel is transmitted via thePhysical Downlink Control Channel. The acknowledgement information forthe Uplink Shared Channel is called a PHICH (Physical Hybrid ARQIndicator Channel) or an ACK/NACK.

In this case, the cell with the different frequency may be a cell of theEvolved UTRA and UTRAN system or a cell of another system such as GSM,WCDMA, TDD-CDMA, CDMA-2000, or WiMAX.

Specifically, it is determined whether the sub-frame in which thePhysical Downlink Control Channel is transmitted is included in theMeasurement gap, whether the sub-frame in which the UL-SCH istransmitted is included in the Measurement gap, or whether the sub-framein which an ACK/NACK (PHICH) for the UL-SCH is transmitted is includedin the Measurement gap, with respect to initial transmission and secondtransmission from the user equipment terminal (UE). When it isdetermined that the sub-frame in which the Physical Downlink ControlChannel is transmitted is included in the Measurement gap, that thesub-frame in which the UL-SCH is transmitted is included in theMeasurement gap, or that the sub-frame in which the ACK/NACK (PHICH) forthe UL-SCH is transmitted is included in the Measurement gap, theprocess of the Measurement Gap Check returns NG (failed). Otherwise, theprocess of the Measurement Gap Check returns OK. The Measurement gaprefers to a time interval during which the user equipment terminal (UE)measures a cell with a different frequency for the purpose ofdifferent-frequency handover or different-system handover. During thetime interval, communications cannot be performed and therefore, theuser equipment terminal (UE) cannot receive the Physical DownlinkControl Channel. For the same reason, the user equipment terminal (UE)cannot transmit the Uplink Shared Channel and cannot receive theACK/NACK (PHICH).

When the result of the Measurement Gap Check is determined as NG, theuser equipment (UE) terminal is excluded from a target of the schedulingprocess. When the user equipment terminal (UE) is excluded from a targetof the scheduling process for initial transmission, the schedulingcoefficients are not calculated in step S732, and as a result, thescheduling process for initial transmission is not performed.

When the result of the Measurement Gap Check is determined as OK, theprocess goes to step S711 in which Half Duplex Check is performed.

In this example, the Measurement Gap Check is not performed for thethird transmission or later. Although the Measurement Gap Check isperformed for the initial transmission and second transmission in thisexample, it may be performed for the initial transmission, secondtransmission, and third transmission. In other words, the MeasurementGap Check may be performed for any number of transmission times.

In step S711, Half Duplex Check is performed. The Half Duplex refers toa communication scheme in which uplink transmission and downlinktransmission are not performed simultaneously. In other words, in theHalf Duplex mode, uplink transmission and downlink transmission areperformed by the user equipment terminal (UE) at different timings.

In Half Duplex Check, when the user equipment terminal (UE) performsHalf Duplex communications, the following six determinations are made:

-   -   whether the corresponding sub-frame, i.e., the sub-frame in        which the Uplink Shared Channel is transmitted, overlaps the        sub-frame in which the Downlink Common Channel (a        Synchronization Channel (SCH), a Primary Broadcast Channel        (P-BCH), a Dynamic Broadcast Channel (D-BCH), or an MBMS        Channel) is transmitted;    -   whether the corresponding sub-frame, i.e., the sub-frame in        which the Uplink Shared Channel is transmitted, overlaps the        sub-frame in which acknowledge information for the Uplink Shared        Channel transmitted from the user equipment terminal (UE) is        transmitted;    -   whether the corresponding sub-frame, i.e., the sub-frame in        which the Uplink Shared Channel is transmitted, overlaps the        sub-frame in which control information (UL Scheduling Grant or        DL Scheduling Information) for uplink or downlink persistent        scheduling is transmitted;    -   whether the sub-frame in which control information (UL        Scheduling Grant) for the Uplink Shared Channel transmitted in        the corresponding sub-frame is transmitted overlaps the        sub-frame in which the user equipment terminal (UE) transmits        the Uplink Shared Channel;    -   whether the sub-frame in which control information (UL        Scheduling Grant) for the Uplink Shared Channel transmitted in        the corresponding sub-frame is transmitted overlaps the        sub-frame in which the user equipment terminal (UE) transmits        CQI (downlink radio quality information), a Sounding Reference        Signal, a Scheduling Request, or a RACH (Random Access Channel)        Preamble in uplink; and    -   whether the sub-frame in which control information (UL        Scheduling Grant) for the Uplink Shared Channel transmitted in        the corresponding sub-frame is transmitted overlaps the        sub-frame in which the user equipment terminal (UE) transmits        acknowledgement information (ACK/NACK) for the Downlink Shared        Channel in uplink.

If at least one of these results is true among the six determinations,the process of the Half Duplex Check may return NG (failed). Otherwise,the process of the Half Duplex Check may return OK. Further, regardingthe uplink and downlink channels relevant to the determinations, all ofthe corresponding channels may be considered, or only some of thecorresponding channels may be considered. When the result of the HalfDuplex Check is determined as NG (step S711: NG), the user equipmentterminal (UE) is excluded from a target of the scheduling process. Onthe other hand, when the result of the Half Duplex Check is determinedas OK (step S711: OK), the process goes to step S712 in which DRX Checkis performed.

As described above, upon performing downlink reception, the userequipment terminal (UE) in the Half Duplex mode cannot perform uplinktransmission. Therefore, according to the process described above,namely by determining whether downlink transmission is to be performedin the corresponding sub-frame and not allocating the Uplink SharedChannel (RBs for the Uplink Shared Channel) at the timing of downlinkreception, it may become possible to avoid the problem in that the userequipment terminal (UE) in the Half Duplex mode cannot transmit anuplink transmission signal upon performing downlink reception.

Further, in the six determinations described above, each determinationmay be made by considering a switching period required to switch betweendownlink reception and uplink transmission in the user equipmentterminal (UE). More specifically, for example, when the transmissiontiming of the Uplink Shared Channel in the user equipment terminal (UE)or the transmission timing of control information (UL Scheduling Grant)for the Uplink Shared Channel in the base station apparatus overlaps theswitching timing, the result of the Half Duplex Check may be determinedas NG.

In this example, Half Duplex Check is performed with respect to the userequipment terminal (UE) to communicate in the Half Duplex mode. However,the Half Duplex Check may be performed with respect to not only the userequipment terminal (UE) to communicate in the Half Duplex mode but alsothe user equipment terminal (UE) to communicate in the Full Duplex mode.Further, the Half Duplex Check may be performed with respect to all theuser equipment terminals (UEs) to communicate in the Full Duplex mode.Alternatively, the Half Duplex Check may be performed with respect tothe user equipment terminal (UE) communicating in the Full Duplex modeand having path loss between the user equipment terminal (UE) and thebase station apparatus 200 above a threshold. On the other hand, theHalf Duplex Check may not be performed with respect to the userequipment terminal (UE) communicating in the Full Duplex mode and havingpath loss between the user equipment terminal (UE) and the base stationapparatus 200 below the threshold. In this case, uplink transmission anddownlink reception are not performed at the same time; therefore, it maybecome possible to avoid a problem in that “uplink transmission signalin the user equipment terminal (UE) acts as an interference signal to adownlink reception signal; and as a result, quality of the downlinkreception signal is degraded” as described below. Further, the HalfDuplex Check may be performed with respect to the user equipmentterminal (UE) to communicate in the Full Duplex mode in a cell or afrequency band which may be heavily influenced by the problem in that“uplink transmission signal in the user equipment terminal (UE) acts asan interference signal to a downlink reception signal; and as a result,quality of the downlink reception signal is degraded”. On the otherhand, the Half Duplex Check may not be performed with respect to theuser equipment terminal (UE) to communicate in the Full Duplex mode in acell or a frequency band which may not be heavily influenced by theproblem in that “uplink transmission signal in the user equipmentterminal (UE) acts as an interference signal to a downlink receptionsignal; and as a result, quality of the downlink reception signal isdegraded”.

Next, in step S712, DRX (discontinuous reception) Check is performed.When the user equipment terminal (UE) performs DRX, that is, when theuser equipment terminal (UE) is in a DRX mode, the Uplink Shared Channel(RBs for the Uplink Shared Channel) is not allocated to the userequipment terminal (UE).

Specifically, it is determined whether the user equipment terminal (UE)is in the DRX mode. When it is determined that the user equipmentterminal (UE) is in the DRX mode, the process of the DRX Check returnsNG (failed). Otherwise, the process of the DRX Check returns OK.

When the result of the DRX Check is determined as NG, the user equipmentterminal (UE) is excluded from a target of the scheduling process forinitial transmission. When the user equipment terminal (UE) is excludedfrom a target of the scheduling process for initial transmission, thescheduling coefficients are not calculated in step S732, and as aresult, the scheduling process for initial transmission is notperformed.

When the result of the DRX Check is determined as OK, the process goesto step S714 in which UL Sync Check is performed.

Next, in step S714, Uplink Synchronization Check (UL Sync Check) isperformed. In this step, when the uplink synchronization state of theuser equipment terminal (UE) is out of synchronization or when uplinkdedicated resources are released, the Uplink Shared Channel (RBs for theUplink Shared Channel) is not allocated to the user equipment terminal(UE). The uplink dedicated resources refer to resources for CQI, aScheduling Request, and a Sounding Reference Signal transmitted inuplink.

Specifically, the base station apparatus 200 determines whether theuplink synchronization state of the user equipment terminal (UE) is outof synchronization. Further, the base station apparatus 200 determineswhether uplink dedicated resources for the user equipment terminal (UE)are released. When it is determined that the uplink synchronizationstate is out of synchronization or that uplink dedicated resources arereleased, the process of the UL Sync Check returns NG (failed).Otherwise, the process of the UL Sync Check returns OK.

When the result of the UL Sync Check is determined as NG, the userequipment terminal (UE) is excluded from a target of the schedulingprocess for initial transmission. When the user equipment terminal (UE)is excluded from a target of the scheduling process for initialtransmission, the scheduling coefficients are not calculated in stepS732, and as a result, the scheduling process for initial transmissionis not performed.

When the result of the UL Sync Check is determined as OK, the processgoes to step S728 in which Low/High Fd Check is performed.

The base station apparatus 200 performs the following detection(determination) for the uplink synchronization state with respect toeach user equipment terminal (UE) 100 _(n) in the RRC_connected state.

The base station apparatus 200 measures reception quality (for example,SIR) of the Sounding RS from the user equipment terminal (UE). When thereception quality is above a predetermined threshold, the uplinksynchronization state is determined as OK. Otherwise, the uplinksynchronization state is determined as NG, i.e., out of synchronization.In this example, the base station apparatus measures reception qualityof the Sounding RS. Alternatively, the base station apparatus maydetermine the uplink synchronization state based on reception quality ofCQI. Alternatively, the base station apparatus may determine the uplinksynchronization state based on both reception quality of the Sounding RSand reception quality of CQI.

Further, the base station apparatus 200 performs the following detection(determination) for the state of uplink dedicated resources with respectto each user equipment terminal (UE) 100 _(n) in the RRC_connectedstate.

The base station apparatus 200 determines that the uplink dedicatedresources are released, when the elapsed time from the timing oftransmitting Timing Advance to the user equipment terminal (UE) the lasttime is greater than an UL Out-of-sync timer. Further, the base stationapparatus 200 determines that dedicated resources are released for theuser equipment terminal (UE) which the base station apparatus 200instructs to release the uplink dedicated resources. With respect to theuser equipment terminal, the base station apparatus 200 assumes thatdedicated resources are released until uplink synchronization isreestablished according to the random access procedure.

As described above, the process of the HARQ Retransmission Check in stepS706 is performed before the process of the UL Sync Check in step S714.Accordingly, when the result of the HARQ Retransmission Check isdetermined as “Retransmission”, the retransmitted UL-SCH is receivedwith respect to the user equipment terminal (UE) even if the result ofthe UL Sync Check is determined as NG.

Next, in step S728, the uplink transmission type is checked (UL Low/HighFd Check is performed). In this step, it is determined whether thetransmission type for the user equipment terminal (UE) is Low Fd or HighFd. The transmission type is managed in common in downlink and uplink.

For example, when the estimated value of Fd for the user equipmentterminal (UE) is less than or equal to a predetermined threshold(Threshold_(Fd,UL)), the transmission type is determined as Low Fd.Otherwise, the transmission type is determined as High Fd.

As the estimated value of Fd, the value reported from the user equipmentterminal (UE) by means of a Measurement report or the like may be used.Alternatively, as the estimated value of Fd, a value calculated based onthe time correlation value of the Sounding Reference Signal transmittedfrom the user equipment terminal (UE) may be used. Alternatively, as theestimated value of Fd, a value calculated based on the DemodulationReference Signal for CQI may be used.

Next, in step S730, Buffer Status Check is performed. In this step, thebase station apparatus does not allocate the Uplink Shared Channel (RBsfor the Uplink Shared Channel) to the user equipment terminal (UE), whenthe user equipment terminal (UE) does not have data to be transmitted.

Specifically, it is determined whether there are available data to betransmitted in the corresponding sub-frame with respect to the userequipment terminal's logical channel groups (a logical channel group #1,a logical channel group #2, a logical channel group #3, and a logicalchannel group #4). When there are no available data to be transmittedwith respect to all the logical channel groups, the process of theBuffer Status Check returns NG (failed). When there are available datato be transmitted with respect to at least one of the logical channelgroups, the process of the Buffer Status Check returns OK. As usedherein, available data to be transmitted refers to available data to beinitially transmitted. When the amount of data in the UL Buffer isgreater than zero (0), it is determined that there are “available datato be initially transmitted”. The definition of the amount of data inthe UL Buffer will be described below. Although four types of the userequipment terminal's logical channel groups (the logical channel group#1, the logical channel group #2, the logical channel group #3, and thelogical channel group #4) are used in this example, a similar processcan be applied to the case where five or more types of logical channelgroups are used. Also, a similar process can be applied to the casewhere three or less types of logical channel group is used. Also, asimilar process can be applied to the case where only one type oflogical channel group is used.

An exceptional process may be performed in the Buffer Status Check asfollows.

When inter-eNB handover (handover between base station apparatus) issupposed to be performed by the user equipment terminal (UE), it isassumed that there are no available data (data for the logical channelgroup #1, the logical channel group #2, the logical channel group #3,and the logical channel group #4) to be transmitted with respect to theuser equipment terminal. For retransmission data, however, the userequipment terminal (UE) transmits the retransmission data, since theprocess in step S730 is skipped due to “retransmission” in step S706.

When the base station apparatus receives from the user equipmentterminal (UE) “resource allocation request for the UL-SCH: REQUESTING”by means of the Scheduling request and uplink radio resources (UL-SCH)have not been allocated to the user equipment terminal (UE) since thebase station apparatus has received the Scheduling request, it isassumed that there are available data to be transmitted with respect tothe logical channel group #1.

When the base station apparatus does not receive the Buffer StatusReport at the reception timing of the UL-SCH, even though the basestation apparatus allocates uplink radio resources (UL-SCH) in responseto the Scheduling request, the base station again assumes that the basestation apparatus receives from the user equipment terminal (UE) the“resource allocation request for the UL-SCH: REQUESTING” by means of theScheduling request and uplink radio resources (UL-SCH) have not beenallocated to the user equipment terminal (UE) since the base stationapparatus has received the Scheduling request. This assumption is madewhen the base station apparatus does not receive the Buffer StatusReport at the timing of initial transmission or later without waitingfor the maximum number of retransmission times.

Both when persistent resources are reserved in the correspondingsub-frame (when the process in step S705 is performed) and whenpersistent resources are not reserved in the corresponding sub-frame(when the process in step S705 is not performed), the following processis performed with respect to the logical channel group to whichpersistent scheduling is applied:

1) when the amount of data in the UL Buffer is greater than or equal toa threshold Threshold_(data) _(—) _(size,UL), it is assumed that “thereare available data to be transmitted” with respect to the logicalchannel group; and

2) when the amount of data in the UL Buffer is less than the thresholdThreshold_(data) _(—) _(size,UL), it is assumed that “there are noavailable data to be transmitted” with respect to the logical channelgroup.

In this manner, when the amount of data in the UL Buffer is less thanthe threshold Threshold_(data) _(—) _(size,UL), it is assumed that“there are no available data to be transmitted” with respect to thelogical channel group. Accordingly, it may become possible to preventdata to be transmitted with persistent resources, i.e., data with asmall data size, from being transmitted in sub-frames other than thesub-frames in which the persistent resources are allocated.Specifically, assuming that persistent resources are not reserved (theprocess in step S705 is not performed), when the determination based onthe data size is not made, data to be transmitted with persistentresources may be transmitted in sub-frames in which persistent resourcesare not allocated. As a result, data to be transmitted may not be foundin the sub-frame in which persistent resources are allocated, andthereby the transmission efficiency is reduced. In this case, thethreshold Threshold_(data) _(—) _(size,UL) may be set to the maximumdata size with which persistent resources can be transmitted or a littlegreater value than the maximum data size.

When the result of the Buffer Status Check is determined as NG, the userequipment terminal (UE) is excluded from a target of the schedulingprocess for initial transmission. When the user equipment terminal (UE)is excluded from a target of the scheduling process for initialtransmission, the scheduling coefficients are not calculated in stepS732, and as a result, the scheduling process for initial transmissionis not performed.

On the other hand, when the result of the Buffer Status Check isdetermined as OK, a logical channel group with the highest prioritylevel is selected and the process goes to step S732 in which SchedulingCoefficient Calculation is performed. In other words, the base stationapparatus calculates the scheduling coefficients based on the logicalchannel group with the highest priority level among data types retainedby the user equipment terminal. Specifically, when there are plurallogical channel groups for the user equipment terminal (UE), the basestation apparatus does not calculate the scheduling coefficients withrespect to all the plural logical channel groups, but calculates thescheduling coefficients with respect to the logical channel group withthe highest priority level, and thereby the workload in the base stationapparatus 200 can be reduced.

Next, in step S732, Scheduling Coefficient Calculation is performed. Inthis step, with respect to the logical channel group with the highestpriority level determined in Section 4.1.9, the scheduling coefficientsare calculated based on the following evaluation equation.

Tables 5-1 and 5-2 show parameters set via the external interface (I/F).Table 6 shows parameters for each logical channel group of the userequipment terminal (UE).

TABLE 5-1 List of input parameters for the scheduler (The subscript LCGrefers to the logical channel group.) Set with Parameter respect No nameto each Remarks 1 A_(LCG) Logical This is a Priority Class channelpriority level coefficient group based on the logical channel group. 2F_(LCG) Logical This is a transmission (t_(No) _(—) _(allocated))channel resource allocation group priority level coefficient used topreferentially transmit data to UE to which transmission resources arenot allocated according to dynamic scheduling. A time interval t_(No)_(—) _(allocated) during which transmission resources are not allocatedaccording to dynamic scheduling is defined as an elapsed time from thetiming when the preceding CRC result of the UL-SCH including logicalchannels belonging to the corresponding logical channel group isdetermined as OK. If the CRC result of the UL-SCH including logicalchannels belonging to the corresponding logical channel group is neverdetermined as OK, the time interval t_(No) _(—) _(allocated) is definedas an elapsed time from the timing when information about the amount ofdata in the buffer (the amount of data is other than zero (0)) withrespect to the logical channel group is reported from the user equipmentterminal. This value is set based on the buffer residence time t_(No)_(—) _(allocated) as follows. If t_(No) _(—) _(allocated) < Th_(LCG)^((No) _(—) ^(allocated, 1)), then F_(LCG) (t_(No) _(—) _(allocated)) =0.0 If Th_(LCG) ^((No) _(—) ^(allocated,1)) =< t_(No) _(—) _(allocated)< Th_(LCG) ^((N) _(—allocated, 2)) , then${F_{LCG}\left( t_{{No}\_ {allocate}d} \right)} = \frac{t_{{No}\_ {allocated}} - {Th}_{LCG}^{({{{No}\_ {allocated}},1})}}{{Th}_{LCG}^{({{{No}\_ {allocated}},2})} - {Th}_{LCG}^{({{{No}\_ {allocated}},1})}}$(When Th_(LCG) ^((No) _(—) ^(allocated, 1)) = Th_(LCG) ^((No) _(—)^(allocated, 2)) , this process is not performed.) If Th_(LCG) ^((No)_(—) ^(allocated, 2)) =< t_(No) _(—allocated) , then F_(LCG) (t_(No)_(—) _(allocated)) = 1.0

TABLE 5-2 List of input parameters for the scheduler (The subscript LCGrefers to the logical channel group.) Set with respect No Parameter nameto each Remarks 3 Th_(LCG) ^((No) ^(—) ^(Allocated,1)) Priority This isa first class threshold related to the time interval during whichtransmission resources are not allocated according to dynamicscheduling. 4 Th_(LCG) ^((No) ^(—) ^(Allocated,2)) This is a secondthreshold related to the time interval during which transmissionresources are not allocated according to dynamic scheduling. 5G(flag_(SR)) UE This is a Scheduling request priority level coefficientgiven to preferentially transmit data to UE from which the base stationapparatus receives “allocation request for the PUSCH: REQUESTING” bymeans of the Scheduling request and to which uplink radio resources(PUSCH) have not been allocated since the base station apparatus hasreceived the Scheduling request. In the corresponding sub-frame, thisvalue is set based on a value flag_(SR) related to the corresponding UE.For example, when flag_(SR) = 0, G(0) is set to a fixed value 1.0 (G(0)= 1.0), and only when flag_(SR) = 1, this value is set via the externalinterface (I/F). When the base station apparatus receives from the UE“allocation request for the PUSCH: REQUESTING” by means of theScheduling request and when uplink radio resources (PUSCH) have not beenallocated to the UE since the base station apparatus has received theScheduling request, flag_(SR) is set equal to one (flag_(SR) = 1).Otherwise, flag_(SR) is set equal to zero (flag_(SR) = 0). 6 R_(PC)^((target)) Logical This is a target data channel rate (bits/sub-frame).group 7 α^((PL)) UE This is a weighting coefficient with respect to thepriority level based on path loss (Pathloss). 8 α_(LCG) ^((No) ^(—)^(allocated)) Logical This is a weighting channel coefficient with grouprespect to the priority level based on the transmission interval duringwhich transmission resources are not allocated according to dynamicscheduling. 10 α_(LCG) ^((rate)) Logical This is a weighting channelcoefficient with group respect to the priority level based on an AverageData Rate. 11 δ′_(LCG) Logical This is a convergence channel value of auser data group rate averaged forgetting coefficient for R _(n,k). 12Scheduling Logical This is an index of a priority group channelScheduling priority index group group set for each logical channelgroup. The UEs are prioritized in the order of the Scheduling prioritygroup (Scheduling priority group: High -> Middle -> Low). In eachScheduling priority group, the UEs are prioritized based on thescheduling coefficients. The priority level is determined such as High >Middle > Low.

TABLE 6 List of input parameters for the scheduler (The subscript LCGrefers to the logical channel group.) Parameter No. name Remarks 1 R_(n)This parameter indicates an Instantaneous transmittable Data Rate(bits/sub-frame) of UE #n, as described below. This parameter iscalculated based on the following equation with reference to theUL_TF_related_table. R_(n) = UL_Table_TF_SIZE (RB_all,└SIR_(estimated)┘) where RB_all is the number of RBs across the systemband. Further, SIR_(estimated) is calculated across the system band.Alternatively, SIR_(estimated) may be the maximum value of plural setsof SIR_(estimated) which are calculated across narrower bands.Alternatively, SIR_(estimated) may be selected, based on thetransmission type, from both the value calculated across the system bandand the maximum value of plural sets of SIR_(estimated) which arecalculated across narrower bands. 2 R _(n,k) This parameter indicates anAverage Data Rate (bits/sub-frame) of a logical channel group #k of UE#n. R _(n,k) (TTI) = δ_(n,k) * R _(n,k) (TTI − 1) + (1 − δ_(n,k)) *r_(n,k) r_(n,k): instantaneous data rate As the initial value of R_(n,k), R_(n,k) calculated in the sub-frame is used. δ_(n,k): forgettingcoefficient which is a variable changing for each calculation period, asdescribed in step S732 (Scheduling Coefficient Calculation). Calculationof R _(n,k) is performed in every sub-frame based on an updating timing(step S732 (Scheduling Coefficient Calculation) with respect to not onlya logical channel group with the highest priority level but also anyother logical channel groups.

Based on the input parameters in Tables 5-1, 5-2, and 6, the schedulingcoefficient C_(n) of the logical channel group #h with the highestpriority level of the user equipment terminal (UE) #n is calculatedaccording to the following equation ([Equation 14]).

C _(n) =A _(highest)×α^((PL)) ·R _(n)×(1+α_(highest) ^((No) ^(—)^(allocated)) ·F _(highest)(t _(No) _(—)_(allocated)))×G(flag_(SR))×exp(α_(highest) ^((rate))·(R _(highest)^((target)) − R _(n,highest)))  [Equation 14]

Namely, when the base station apparatus selects a user equipmentterminal to which radio resources are allocated, the base stationapparatus may select the user equipment terminal based on a signal(Scheduling request) by means of which the user equipment terminalrequests allocation of the Uplink Shared Channel (RBs for the UplinkShared Channel). In addition, the base station apparatus may calculate acoefficient representing a priority level for allocating radio resourcesbased on at least one of a priority class of data; radio quality of thereference signal transmitted from the user equipment terminal (forexample, SIR of the Sounding Reference Signal); a time duration duringwhich the shared channel (RBs for the shared channel) is not allocated;whether the base station apparatus receives the Scheduling request; anaverage transmission rate; and a target transmission rate.

In the case of intra-eNB handover (Intra-eNB HO), measured values andcalculated values used for the scheduling process are not transferred toa Target eNB (eNB of the handover destination).

In step S732, an Average Data Rate is measured. The Average Data Rate iscalculated using the following equation ([Equation 15]).

R _(n,k) =R _(n,k)(N _(n,k)=1)

R _(n,k)=δ_(n,k) · R _(n,k)·(TTI−1)+(1−δ_(n,k))·r _(n,k)(N_(n,k)>1)  [Equation 15]

where N_(n,k)(1, 2, . . . ) denotes the number of times updating theAverage Data Rate. However, in the sub-frame where N_(n,k)=0, thefollowing equation ([Equation 16]) is applied.

R _(n,k)=R_(n,k)  [Equation 16]

Further, a forgetting coefficient δ_(n,k) is calculated as follows.

δ_(n,k)=min(1−1/N _(n,k), δ_(PCn,k))  [Equation 16]

An updating timing of the Average Data Rate is based on “every sub-framewhere the amount of data in the UL Buffer is not zero (0) for eachlogical channel group”. Further, r_(n,k) is calculated as “a Payloadsize supposed to be transmitted from the user equipment terminal (UE)”.It should be noted that r_(n,k) is calculated both when the UplinkShared Channel is initially transmitted in the corresponding sub-frameand when the Uplink Shared Channel is retransmitted in the correspondingsub-frame. Namely the calculation of the Average Data Rate is performedbased on any of the following operations in the sub-frame when theAverage Data Rate is to be updated (the sub-frame where the amount ofdata in the UL Buffer of the logical channel group #k is not zero).

1) For a user equipment terminal (UE) that transmits data, the AverageData Rate is calculated assuming that:

r _(n,LCG1)=min(Payload size, UL_Buffer_(n,LCG1));

r _(n,LCG2)=max(0, min(Payload size−r _(n,LCG1) , UL_Buffer_(n,LCG2)));

r _(n,LCG3)=max(0, min(Payload size−r _(n,LCG1) −r _(n,LCG2) ,UL_Buffer_(n,LCG3))); and

r _(n,LCG4)=max(0, min(Payload size−r _(n,LCG1) −r _(n,LCG2) −r_(n,LCG3) , UL_Buffer_(n,LCG4))).

The Payload size is a value specified by the UL Scheduling Grant.

2) For a user equipment terminal (UE) that has not transmitted data, theAverage Data Rate is calculated assuming “r_(n,k)=0”.

As described above, the Average Data Rate is calculated based on thedata size (r_(n,k)) of each logical channel group, which is estimatedfrom the amount of data (Buffer_(n,k)) in the buffer for each logicalchannel group, assuming that the user equipment terminal (UE)preferentially maps logical channels belonging to a higher logicalchannel group to the MAC PDU (UL-SCH).

The amount of data in the UL Buffer is defined as follows. The amount ofdata UL_Buffer_(n,k) in the UL Buffer for a logical channel group #k ofthe user equipment terminal (UE) #n is calculated as follows.

$\begin{matrix}\left\lbrack {{Equation}\mspace{14mu} 17} \right\rbrack & \; \\{{UL\_ Buffer}_{n,k} = {{Buffer}_{n,k}^{({BSR})} - {\sum\limits_{j}{{{Size}_{n,k}^{({{CRC}:{OK}})}(j)}.}}}} & \;\end{matrix}$

where Buffer_(n,k) ^((BSR)) denotes the amount of data in the buffer forthe logical channel group #k of the user equipment terminal (UE) #n,which is calculated based on the Buffer Status Report reported from theuser equipment terminal (UE).

$\sum\limits_{j}{{Size}_{n,k}^{({{CRC}:{OK}})}(j)}$

denotes the sum of data sizes for the logical channel group #k of theuser equipment terminal (UE) #n, which has been included in the UL-SCHwhere the CRC result is OK since the timing of making the Buffer StatusReport (until the current timing).

Namely, the base station apparatus calculates the amount of data in thebuffer of the user equipment terminal based on both information aboutthe amount of data in the buffer (Buffer Status Report (BSR)) reportedfrom the user equipment terminal and the amount of data which has beenreceived from the user equipment terminal since the base stationapparatus has received the information.

Next, in step S734, N_(Scheduling) indicating the number of userequipment terminals (UEs) for which the scheduling coefficient iscalculated is incremented by one. In step S736, a value of “n”indicating the index of the user equipment terminal (UE) is incrementedby one.

Next, in step S738, it is determined whether the value of “n” is lessthan or equal to N. When it is determined that the value of “n” is lessthan or equal to N, the process goes back to step S702.

On the other hand, when it is determined that the value of “n” isgreater than N, the process goes to step S740 in which UE Selection isperformed. In this step, the user equipment terminal (UE) to which radioresources are to be allocated according to dynamic scheduling (only forinitial transmission) is selected in the corresponding sub-frame.

First, according to the following equation, the number of user equipmentterminals (UEs) N_(UL-SCH) to which radio resources are to be allocatedaccording to dynamic scheduling is calculated. N_(Scheduling) denotesthe number of user equipment terminals (UEs) for which the schedulingcoefficient is calculated (see step S732 in FIG. 7B). N_(retransmission)denotes the number of user equipment terminals (UEs) which performretransmission in the corresponding sub-frame (see FIG. 7B).

N _(UL-SCH,tmp)=min(N _(Scheduling) , N _(ULMAX) −N _(retransmisson))

min(x, y) denotes a function which returns a smaller value amongarguments “x” and “y”.

Next, top N_(UL-SCH,tmp) “user equipment terminals (UEs) to which radioresources are to be allocated according to dynamic scheduling (only forinitial transmission)” are selected in descending order of thescheduling coefficients calculated in step S732 for each Schedulingpriority group in the logical channel group with the highest prioritylevel. As used herein, the Scheduling priority group refers to a groupprioritized in the scheduling process and a scheduling priority group towhich the logical channel group is to belong is defined with respect toeach logical channel group.

Namely, the base station apparatus 200 selects “user equipment terminals(UEs) to which radio resources are to be allocated according to dynamicscheduling (only for initial transmission)”

High (1st)->High (2nd)-> . . . ->Middle (1st)->Middle (2nd)-> . . .->Low (1st)->Low (2nd)-> . . .

In this example, the Scheduling priority group has three types, High,Middle, and Low. However, for example, four more types of Schedulingpriority groups may be defined or two or less types of Schedulingpriority groups may be defined.

As described above, it may become possible to calculate the schedulingcoefficient with respect to each user equipment terminal that isdetermined to be capable of initial transmission, by performing a loopprocess with respect to “n” which is an index of the user equipmentterminals (UE index). Further, the radio resources may be allocated tothe user equipment terminal having a greater calculated schedulingcoefficient value, and thereby it may become possible to determine theuser equipment terminals to which the radio resources (Uplink SharedChannel) are to be allocated based on a priority level of data; uplinkradio quality; a time duration during which the shared channel (RBs forthe shared channel) is not allocated; whether the base station apparatusreceives the Scheduling request; an average transmission rate; or atarget transmission rate.

Next, Uplink TFR Selection (UL TFR Selection) performed in step S208 isdescribed with reference to FIG. 8.

FIG. 8 shows a procedure of UL TFR Selection. According to thisprocedure, the base station apparatus 200 reserves radio resources (RBs)for the Physical Random Access Channel (PRACH), reserves prohibitedradio resources (RBs) or guard RBs, reserves radio resources (RBs) forthe UL-SCH to which persistent scheduling is applied, and thendetermines a transmission format for the UL-SCH to which dynamicscheduling is applied and allocates radio resources for the UL-SCH towhich dynamic scheduling is applied (including for both initialtransmission and retransmission).

In step S802, resource block allocation for the Physical Random AccessChannel (PRACH) and the Physical Uplink Control Channel (PUCCH) to befrequency-multiplexed with the Physical Uplink Shared Channel (PUSCH)(RB allocation for PRACH and PUCCH) is performed. In this step, radioresources are allocated to the Random Access Channel (RACH) and thePhysical Uplink Control Channel (PUCCH) before radio resources areallocated to the shared channel.

Specifically, when a RACH preamble is transmitted in the correspondingsub-frame, radio resources (RBs) for the PRACH and N_(RACH) RBs on bothsides of the PRACH are reserved (6+2*N_(RACH) RBs are reserved intotal). In other words, the radio resources (RBs) for the PRACH andN_(RACH) RBs on both sides of the PRACH (6+2*N_(RACH) RBs in total) areexcluded from candidates for RBs to be allocated to the UL-SCH to whichdynamic scheduling is applied. For example, N_(RACH) is a valuedesignated via the external input interface (I/F). For example, N_(RACH)is selected from 0, 1, 2, and 3.

The PRACH preamble corresponds to a Message-1 in the random accessprocedure. The number of resource blocks in which the PRACH preamble istransmitted is equal to six (6).

In addition, radio resources (RBs) for the Physical Uplink ControlChannel (PUCCH) are reserved. In other words, the radio resources (RBs)to be allocated to the Physical Uplink Control Channel (PUCCH) areexcluded from candidates for RBs to be allocated to the UL-SCH to whichdynamic scheduling is applied.

In step S804, RB allocation for Guard RBs is performed. When the systemis frequency-adjacent (adjacent in the frequency direction) to aheterogeneous radio communication system (WCDMA system), for example,radio resources other than the resource placed at the end of the systembandwidth are allocated.

Specifically, Guard RBs are reserved. In other words, the Guard RBs areexcluded from candidates for RBs to be allocated to the UL-SCH to whichdynamic scheduling is applied.

In this example, the heterogeneous radio communication system is theWCDMA system. Alternatively, the heterogeneous radio communicationsystem may be a GSM system, a CDMA-2000 system, a PHS system, or thelike.

The Guard RBs are implemented as guard bands for the purpose of reducingadjacent channel interference with a frequency-adjacent system. Two setsof Guard RBs may be reserved for both ends of adjacent systems. Itshould be noted that the Physical Uplink Control Channel (PUCCH) ismapped to the end of the system band regardless of the presence orabsence of the Guard RBs.

Alternatively, large resources for the PUCCH may be reserved, andthereby interference with the heterogeneous radio communication systemscan be reduced. Specifically, the base station apparatus may notallocate frequency resources at the end of system bands to the UplinkShared Channel (UL-SCH), and thereby interference with the heterogeneousradio communication systems can be reduced.

In step S806, RB allocation for Persistent Scheduling is performed. Inthis step, allocation according to persistent scheduling is performedbefore allocation according to dynamic scheduling is performed.

Specifically, radio resources (RBs) for the persistent resources, whichare reserved in step 705, are reserved. Further, with regard to the userequipment terminal to which persistent resources are to be allocated andwhose data are to be transmitted, which is determined in step S703,radio resources (RBs) are reserved. In addition, with regard to theUplink Shared Channel (UL-SCH) to which persistent scheduling is appliedfor retransmission, radio resources may be reserved.

When persistent resources are allocated in the corresponding sub-frameto the “user equipment terminal (UE) to which radio resources are to beallocated according to dynamic scheduling (only for initialtransmission)”, the persistent resources are reserved. The RBscorresponding to the persistent resources are not used for UL TFRSelection for the UL-SCH to which dynamic scheduling is applied. In thismanner, even when radio resources are to be allocated according todynamic scheduling to the user equipment terminal (UE) to whichpersistent resources are allocated, the persistent resources arereserved, and thereby the collision can be avoided among uplink signalswhich are transmitted when the UL Scheduling Grant for dynamicscheduling is not successfully received by the user equipment terminal(UE).

With reference to FIGS. 9 and 10, an effect of reserving persistentresources when radio resources are to be allocated according to dynamicscheduling to the user equipment terminal (UE) to which the persistentresources are allocated is described below. In FIGS. 9 and 10, two userequipment terminals (UE #A and UE #B) are used. Persistent resources areallocated to UE #A in the corresponding sub-frame and resources areallocated according to dynamic scheduling to UE #A and UE #B.

In FIG. 9 (1), persistent resources for UE #A are released and radioresources are allocated to UE #A and UE #B. In this case, radioresources allocated to UE #B according to dynamic scheduling may overlapthe persistent resources for UE #A, for example. When UE #A cannotsuccessfully receive the UL Scheduling Grant for dynamic scheduling, UE#A transmits the UL-SCH using the persistent resources. As a result, theUL-SCH for UE #A may conflict with the UL-SCH for UE #B a shown in FIG.10 (1).

On the other hand, in FIG. 9 (2), persistent resources for UE #A arereserved and radio resources are allocated to UE #A and UE #B. In thiscase, radio resources allocated to UE #B according to dynamic schedulingdo not overlap the persistent resources for UE #A, for example. When UE#A cannot successfully receive the UL Scheduling Grant for dynamicscheduling, UE #A transmits the UL-SCH using the persistent resources.In this case, the UL-SCH for UE #A does not conflict with the UL-SCH forUE #B a shown in FIG. 10 (2).

In this example, radio resources refer to frequency resources, forexample.

In step S806, when the base station cannot allocate to the userequipment terminal resource blocks for the Uplink Shared Channel(UL-SCH) to which persistent scheduling is applied for retransmission,the base station may transmit the ACK via the PHICH. In this case, theACK is used to temporarily stop retransmission of the Uplink SharedChannel (UL-SCH) to which persistent scheduling is applied.

In step S808, resource block allocation for the Message-3 in the randomaccess procedure (RB allocation for Message-3 (RACH)) is performed. Inthis step, radio resources are allocated to the Message-3(s) in therandom access procedure before radio resources are allocated to theUplink Shared Channel (UL-SCH) according to dynamic scheduling.

Radio resources (RBs) for the Message-3s in the random access procedureare reserved. Specifically, radio resources (RBs) for the Message-3s inthe random access procedure (including for both initial transmission andretransmission) are excluded from candidates for RBs to be allocated tothe UL-SCH to which dynamic scheduling is applied.

In the following descriptions, the Message-3s in the random accessprocedure are merely referred to as Message-3s.

The RB allocation for the Message-3s for initial transmission isperformed according to the following five-step procedure. The RBallocation for retransmission is the same as the RB allocation forinitial transmission. The RB allocation to the Message-3s forretransmission may be considered as the RB allocation for initialtransmission.

(1) It is determined whether there are available RBs to be allocated tothe Message-3s. When there are available RBs to be allocated to theMessage-3s, next step (2) is performed. Otherwise, this process comes toan end. The “available RBs to be allocated to the Message-3s” correspondto RBs other than the RBs allocated to the Physical Random AccessChannel (PRACH) and the Physical Uplink Control Channel (PUCCH), theGuard RBs, and the RBs allocated to the UL-SCH to which persistentscheduling is applied.

(2) Message-3s to be transmitted in the corresponding sub-frame arearranged in ascending order of quality. The order of plural Message-3swith the same quality is arbitrarily determined. The Message-3 withlowest quality is indexed as #0, and thereby the Message-3s are indexedas #0, #1, #2, #3, . . . . When only one type of quality is used, theorder of plural Message-3s is arbitrarily determined.

(3) The following process is performed according to a Hopping mode.

The Hopping mode is a parameter designated via the external inputinterface (I/F).

If the Hopping mode is zero (Hopping mode==0), the base stationapparatus generates Message-3 sets, each of which includes a pair of twoMessage-3s selected on a two-by-two basis from the beginning ofMessage-3s in the order of #0, #1, #2, #3, . . . . The Message-3 setsare indexed as #a, #b, #c, . . . (the Message-3 set #a includes theMessage-3s #0 and #1, the Message-3 set #b includes the Message-3s #2and #3, and so on). When the number of Message-3s is odd-numbered, thelast Message-3 constitutes one Message-3 set.

The base station apparatus allocates “RBs which have reflective symmetryat the center of the system band” to the Message 3 sets in the order of#a, #b, #c, . . . . Specifically, the base station apparatus allocatesRBs to the Message-3 sets in the order of #a, #b, #c, . . . beginningfrom the ends of the system band. The number of RBs allocated to theMessage-3s is determined based on quality information. For example, whenthe quality information indicates “high quality”, two RBs are allocated.For example, when the quality information indicates “low quality”, fourRBs are allocated. Alternatively, the number of RBs may be determinedregardless of quality information. For example, this quality informationis included in the Message-1 in the random access procedure.

When the number of RBs in one Message-3 in a particular Message-3 set isdifferent from the number of RBs in the other Message-3 in theparticular Message-3 set, the base station apparatus uses a largernumber of RBs to allocate the “RBs which have reflective symmetry at thecenter of the system band”.

The base station apparatus 200 may notify the user equipment terminalthat the Message-3s are transmitted with hopping, as informationincluded in the Uplink Scheduling Grant to be mapped to the PhysicalDownlink Control Channel (PDCCH), for example.

The base station apparatus does not allocate RBs which are placedoutside the RBs allocated to the Message-3s to the UL-SCH to whichdynamic scheduling is applied. In addition, when the number ofMesssage-3s is odd-numbered, the base station apparatus does notallocate the RBs used for transmitting the last Message-3 to the UL-SCHto which dynamic scheduling is applied.

In this example, frequency resources (RBs) after hopping are the RBswhich have reflective symmetry at the center of the system band.Alternatively, frequency resources (RBs) after hopping may be RBs whichare shifted from the original RBs by a half of the system bandwidth.

Otherwise (if the Hopping mode is not zero), the base station apparatusallocates RBs to Message-3s as follows. The number of RBs allocated tothe Message-3s is determined based on quality information. For example,when the quality information indicates “high quality”, two RBs areallocated. For example, when the quality information indicates “lowquality”, four RBs are allocated. Alternatively, the number of RBs maybe determined regardless of quality information. For example, thisquality information is included in the Message-1 in the random accessprocedure.

#0: #0 is allocated to the RB with the lowest frequency among availableRBs to be allocated to the Message-3s;

#1: #1 is allocated to the RB with the highest frequency among availableRBs to be allocated to the Message-3s;

#2: #2 is allocated to the RB with the next lowest frequency amongavailable RBs to be allocated to the Message-3s;

#3: #3 is allocated to the RB with the next highest frequency amongavailable RBs to be allocated to the Message-3s; and so on.

(This process continues until RBs are allocated to all the Message-3s.)

(4) The modulation scheme for all the Message-3s is determined as QPSK.

(5) Transmission power of the Uplink Scheduling Grant for each Message-3is determined based on quality information. For example, when thequality information indicates “high quality”, transmission power isdetermined as low transmission power. For example, when the qualityinformation indicates “low quality”, transmission power is determined ashigh transmission power. Alternatively, transmission power may bedetermined regardless of quality information. For example, this qualityinformation is included in the Message-1 in the random access procedure.

When no more RBs can be allocated to the Message-3s during this process,the process comes to an end. The base station apparatus does nottransmit a Message-2 (RACH response) in the random access procedure tothe user equipment terminal (UE) which has a Message-3 to which no RB isallocated. Alternatively, the base station apparatus may transmit theMessage-2 (RACH response) in the random access procedure in the nextsub-frame.

In step S809, Setting of RB allocation mode is performed. In this step,the RB allocation mode is determined. The UL RB allocation mode shown inTable 7 is a parameter designated via the external input interface(I/F). The loop process with respect to the index “j” composed of stepsS812, S810, 5814, 5816, and 5818 is executed based on the selectionorder of user equipment terminals (UEs) specified by the UL RBallocation mode.

TABLE 7 UL RB allocation mode Mode Definition Mode-0 This is a normal RBallocation mode. In this mode, the following selection order of userequipment terminals (UEs) is used. (1st criterion) User equipmentterminals (UEs) for retransmission are selected. Among these userequipment terminals (UEs), a higher selection order is assigned to auser equipment terminal (UE) with a longer elapsed time from initialtransmission. When the elapsed time is the same for plural userequipment terminals (UEs), the selection order is arbitrary determined.(2nd criterion) User equipment terminals for initial transmission areselected. Among these user equipment terminals (UEs), a higher selectionorder is assigned to the “candidates for the user equipment terminals(UEs) to which radio resources are to be allocated according to dynamicscheduling” determined in Section 4.1.11. Mode-1 This is a RB allocationmode in which RBs at the end of the system band are allocated to userequipment terminals with low path loss (Pathloss). (1st criterion) Userequipment terminals for retransmission are selected. Among these userequipment terminals (UEs), a higher selection order is assigned to auser equipment terminal (UE) with lower path loss. (2nd criterion) Userequipment terminals for initial transmission are selected. Among theseuser equipment terminals (UEs), a higher selection order is assigned toa user equipment terminal (UE) with lower path loss. Mode-2 This is a RBallocation mode in which RBs with low frequency are allocated to userequipment terminals with high path loss (Pathloss). (1st criterion) Userequipment terminals for retransmission are selected. Among these userequipment terminals (UEs), a higher selection order is assigned to auser equipment terminal (UE) with higher path loss. (2nd criterion) Userequipment terminals for initial transmission are selected. Among theseuser equipment terminals (UEs), a higher selection order is assigned toa user equipment terminal (UE) with higher path loss. Mode-3 This is aRB allocation mode in which RBs with high frequency are allocated touser equipment terminals with high path loss (Pathloss). (1st criterion)User equipment terminals for retransmission are selected. Among theseuser equipment terminals (UEs), a higher selection order is assigned toa user equipment terminal (UE) with higher path loss. (2nd criterion)User equipment terminals for initial transmission are selected. Amongthese user equipment terminals (UEs), a higher selection order isassigned to a user equipment terminal (UE) with higher path loss.

For example, when the system is frequency-adjacent to a WCDMA system atone end and to an LTE system at the other end, Mode-2 and Mode-3 areselected. Specifically, when the system is frequency-adjacent to theWCDMA system at one end and to the LTE system at the other end, the basestation apparatus allocates radio resources (frequency resources) forthe shared channel, on the side of the WCDMA system and at the end ofthe system band, to a user equipment terminal with lower path loss. Inaddition, the base station apparatus allocates radio resources(frequency resources), on the side of the LTE system and at the end ofthe system band, to a user equipment terminal with higher path loss.

Since the user equipment terminal with low path loss has low uplinktransmission power, interference power affecting the adjacent frequencyband is low. Accordingly, radio resources for the shared channel on theside of the WCDMA system, which is more tolerant to interferencesignals, are allocated to the user equipment terminal with lower pathloss, and thereby degradation of properties in the WCDMA system can bereduced.

For example, when the system is frequency-adjacent to WCDMA systems atboth ends, Mode-1 is selected. Specifically, the base station apparatusallocates radio resources (frequency resources) for the shared channel,at both ends of the system band, to a user equipment terminal with lowerpath loss. In addition, the base station apparatus allocates radioresources (frequency resources), at the center of the system band, to auser equipment terminal with higher path loss.

Since the user equipment terminal with low path loss has low uplinktransmission power, interference power affecting the adjacent frequencyband is low. Accordingly, radio resources for the shared channel at thecenter of the system band are allocated to the user equipment terminalwith higher path loss and radio resources for the shared channel at theend of the system band are allocated to the user equipment terminal withlower path loss, and thereby degradation of properties in the WCDMAsystem can be reduced.

For example, when the system is frequency-adjacent to LTE systems atboth ends, Mode-0 is selected. Specifically, radio resources (frequencyresources) are allocated based on reception power or SIR of thereference signal transmitted from the user equipment terminal or thelike, as described below.

In this case, radio resources can be allocated based on uplink receptionpower, and thereby the system capacity can be improved.

For example, when the frequency (frequency resources) used for uplink isdifferent from the frequency (frequency resources) used for downlink,Mode-2 and Mode-3 may be selected. Specifically, radio resources(frequency resources) for the shared channel which are placed at the endof the system band and near the frequency used for downlink areallocated to a user equipment terminal with lower path loss and radioresources (frequency resources) for the shared channel which are placedat the end of the system band and far from the frequency used fordownlink are allocated to the user equipment terminal with higher pathloss.

Since the user equipment terminal with low path loss has low uplinktransmission power, interference power from the transmitter in the userequipment terminal (i.e., the uplink frequency band) to the receiver inthe user equipment terminal (i.e., the downlink frequency band) is low.Accordingly, radio resources for the Uplink Shared Channel near thedownlink frequency band are allocated to the user equipment terminalwith lower transmission power, and thereby interference power from thetransmitter to the receiver in the user equipment terminal can bereduced. As a result, downlink reception properties can be improved.

Interference power from the transmitter to the receiver becomes higherwhen the uplink transmission bandwidth becomes wider. Accordingly, thebase station apparatus 200 may set an upper limit of the transmissionbandwidth for the Uplink Shared Channel (UL-SCH), and may allocatefrequency resources for the Uplink Shared Channel such that thefrequency bandwidth for the Uplink Shared Channel is less than or equalto the upper limit. According to this process, interference power fromthe transmitter to the receiver in the user equipment terminal can bereduced. As a result, downlink reception properties can be improved.

Further, interference power from the transmitter to the receiver dependson the frequency bands or the system bandwidth used in the mobilecommunication system, the total uplink or downlink bandwidth (passbandwidth) assigned to the frequency bands, or the separation betweenthe uplink frequency and the downlink frequency. Accordingly, Mode-2 orMode-3 may be selected based on the frequency bands or the systembandwidth, the total uplink or downlink bandwidth (pass bandwidth)assigned to the frequency bands, or the separation between the uplinkfrequency and the downlink frequency. In addition, the upper limit ofthe transmission bandwidth for the Uplink Shared Channel may bedetermined based on the frequency bands or the system bandwidth, thetotal uplink or downlink bandwidth (pass bandwidth) assigned to thefrequency bands, or the separation between the uplink frequency and thedownlink frequency. For example, the frequency bands may be “UTRA FDDfrequency bands” defined in TS 25.101.

In step S812, the value of “j” is set equal to one (j=1).

In step S810, RB Remaining Check is performed. It is determined whetherthere are available RBs to be allocated to the UL-SCH to which dynamicscheduling is applied. When there are available RBs to be allocated tothe UL-SCH, the process of the RB Remaining Check returns OK. Otherwise,the process of the RB Remaining Check returns NG (failed).

When the result of the RB Remaining Check is determined as OK, theprocess goes to step S814 in which UL TFR Selection is performed.

When the result of the RB Remaining Check is determined as NG, theprocess of the UL TFR Selection in step S208 comes to an end.

When the result of the RB Remaining Check is determined as NG, the ACKmay be transmitted via the PHICH to the user equipment terminal (UE) towhich the UL Scheduling Grant cannot be transmitted and which performsretransmission. With regard to the user equipment terminal which hastransmitted the ACK (HARQ Process), when the maximum number ofretransmission times has not been reached, it is assumed that the userequipment terminal (UE) has “data to be retransmitted” in the nexttransmission timing according to Synchronous HARQ. In this case, the ACKmeans that retransmission of the Uplink Shared Channel (UL-SCH) istemporarily stopped. In the following, the effect of transmitting theACK via the PHICH to the user equipment terminal (UE) to which the ULScheduling Grant cannot be transmitted and which performs retransmissionis described below. When the user equipment terminal (UE) cannotsuccessfully receive the Uplink Scheduling Grant for retransmission ofthe Uplink Shared Channel (UL-SCH), the user equipment terminal followsinformation (i.e., ACK/NACK) transmitted via the PHICH. When the resultof the RB Remaining Check is determined as NG, the base stationapparatus 200 does not transmit the Uplink Scheduling Grant. As aresult, the user equipment terminal (UE) follows information (i.e.,ACK/NACK) transmitted via the PHICH. When the information transmittedvia the PHICH is the ACK, the user equipment terminal (UE) stopsretransmission of the UL-SCH. Otherwise (in the case of the NACK), theuser equipment terminal (UE) retransmits the UL-SCH using the samefrequency resources as the resources used for previous transmission. Inthis case, when the base station apparatus instructs another userequipment terminal (UE) to transmit the UL-SCH with the correspondingfrequency resources used for the previous transmission, the UplinkShared Channel (UL-SCH) for retransmission by the user equipmentterminal (UE) collides with the Uplink Shared Channel (UL-SCH) fortransmission by the other user equipment terminal (UE). As a result,transmission properties are degraded. When the base station apparatus200 transmits the ACK via the PHICH in the case where the result of theRB Remaining Check is determined as NG, degradation of transmissionproperties can be avoided.

The “available RBs to be allocated to the UL-SCH to which dynamicscheduling is applied” correspond to RBs other than the RBs allocated tothe Physical Random Access Channel (PRACH) and the Physical UplinkControl Channel (PUCCH), the Guard RBs, the RBs allocated to the UL-SCHto which persistent scheduling is applied, the RBs allocated to theMessage-3 in the random access procedure, and the RBs allocated to theUL-SCH to which dynamic scheduling is applied after TFR Selection(including for both retransmission and initial transmission). The totalnumber of “available RBs to be allocated to the UL-SCH to which dynamicscheduling is applied (including for both retransmission andtransmission” is defined as N_(remain) ^((RB)).

The RBs allocated to the UL-SCH to which dynamic scheduling is appliedafter TFR Selection (including for both retransmission and initialtransmission) correspond to the RBs determined in step S814, when thevalue of “j” is less than the current value in the loop process withrespect to the index “j” composed of steps S810, S814, S816, and S818.

In step S814, UL TFR Selection is performed. The base station apparatusdetermines the transport format for the “user equipment terminal (UE) towhich radio resources are to be allocated according to dynamicscheduling (including for both initial transmission andretransmission)”, which is determined in step S204, and allocates RBs.

With reference to FIG. 11A, Uplink TFR Selection in step S814 isdescribed below. According to the following process, RBs are allocatedto a j^(th) “user equipment terminal (UE) to which radio resources areto be allocated according to dynamic scheduling”. FIGS. 12A and 12B showexamples of TF_Related_table.

As shown in FIGS. 12A and 12B, the TF_Related_table may store thecorrespondence between radio resources (the number of resource blocks)available for transmission of the Uplink Shared Channel, uplink radioquality information, and a modulation scheme and a data size used fortransmission of the Uplink Shared Channel. The base station apparatusmay determine the transmission format (the modulation scheme and thedata size) used for the Uplink Shared Channel, with reference to theTF_related_table, based on radio quality of the Sounding ReferenceSignal transmitted from the user equipment terminal (radio qualityinformation calculated based on SIR, for example) and radio resources(the number of resource blocks) available for transmission of the UplinkShared Channel. The data size is determined to be a maximum value whichsatisfies a predetermined error rate, when uplink radio qualityinformation and frequency resources available for the shared channel arefixed. The TF_Related_table may store, as the transmission format, thedata size used for transmission of the Uplink Shared Channel, amodulation scheme used for the Uplink Shared Channel, and the amount offrequency resources used for the Uplink Shared Channel. It should benoted that FIGS. 12A and 12B merely shows example values and valuesother than those shown in FIGS. 12A and 12B may be used. In addition,although FIGS. 12A and 12B show the case where the number of RBs is one(the number of RBs=1) and the case where the number of RBs is two (thenumber of RBs=2), respectively, a similar table can be used in the casewhere the number of RBs is greater than or equal to three.

<Process>

In step S504, the following parameters are provided.

N_(remain) ^((RB)): the number of Remaining RBs

N_(capability): the maximum number of RBs

N_(max,bit): the maximum data size (payload size) which is determinedbased on the UE category

N_(capability) may be set as an internal parameter, may be set as aparameter designated via the upper node, or may be set based oninformation included in the UE capability reported from the userequipment terminal (UE). Using N_(capability), the upper limit offrequency resources used for uplink transmission from the user equipmentterminal (UE) can be provided.

Next, in step S505, the number of available RBs N_(allocated) ^((RB)) tobe allocated to the user equipment terminal (UE) is calculated.

N _(remain) ^((UE)) =N _(UL-SCH) −j+1

$\begin{matrix}\left\lbrack {{Equation}\mspace{14mu} 18} \right\rbrack & \; \\{{N_{remain}^{({UE})} = {N_{{UL} - {SCH}} - j + 1}}{N_{allocated} = {\min\left( {\left\lceil \frac{N_{remain}^{({RB})}}{N_{remain}^{({UE})}} \right\rceil,N_{capability}} \right)}}} & \;\end{matrix}$

It is assumed that available RBs to be allocated to the j^(th) “userequipment terminal (UE) to which radio resources are to be allocatedaccording to dynamic scheduling” are continuous. When the RBs are notcontinuous, the “available RBs to be allocated” are determined as a setof RBs which has the maximum number of available RBs to be allocatedamong continuous available RBs to be allocated. When there are pluralsets of RBs which have the maximum number of available RBs to beallocated, the “RBs to be allocated” are determined as a set of RBs witha lower frequency.

When the number of subcarriers corresponding to N_(allocated) includesfactors other than 2, 3, and 5, N_(allocated) is determined as a maximuminteger among integers which include only factors of 2, 3, 5 for thenumber of subcarriers and which are less than N_(allocated).

Alternatively, N_(allocated) ^((RB)) may be calculated according to thefollowing approach rather than the above-mentioned equation ([Equation18]).

When path loss between the user equipment terminal (UE) and the basestation apparatus 200 is greater than or equal to a perdeterminedthreshold Threshold_(PL,UL), N_(allocated) ^((RB)) may be calculatedaccording to the following equation ([Equation 19]).

$\begin{matrix}\left\lbrack {{Equation}\mspace{14mu} 19} \right\rbrack & \; \\{N_{allocated} = {\min\left( {\left\lceil \frac{N_{remain}^{({RB})}}{N_{remain}^{({UE})}} \right\rceil,N_{{UL},{HighPL}}} \right)}} & \;\end{matrix}$

Otherwise, N_(allocated) ^((RB)) may be calculated according to thefollowing equation ([Equation 20]).

$\begin{matrix}\left\lbrack {{Equation}\mspace{14mu} 20} \right\rbrack & \; \\{N_{allocated} = {\min\left( {\left\lceil \frac{N_{remain}^{({RB})}}{N_{remain}^{({UE})}} \right\rceil,N_{{UL},{LowPL}}} \right)}} & \;\end{matrix}$

Typically, N_(UL,HighPL) is less than N_(UL,LowPL)(N_(UL,HighPL)<N_(UL,LowPL)). The path loss may be calculated based onUPH (UE Power Headroom) reported from the user equipment terminal (UE)and the received level of the Uplink Shared Channel (UL-SCH) or theSounding Reference Signal. The path loss calculated based on UPH (UEPower Headroom) reported from the user equipment terminal (UE) and thereceived level of the Uplink Shared Channel (UL-SCH) or the SoundingReference Signal corresponds to uplink path loss. On the other hand,path loss reported from the user equipment terminal corresponds todownlink path loss.

The effect of calculating N_(allocated) ^((RB)) based on the thresholdThreshold_(PL,UL) and path loss between the user equipment terminal (UE)and the base station apparatus 200 is described below. For example, inan LTE system employing the FDD (Frequency Division Duplexing) scheme,the uplink transmission signal in the user equipment terminal (UE) maybecome an interference signal to the downlink reception signal. As aresult, quality of the downlink reception signal may be degraded.Generally, the user equipment terminal (UE) includes a Duplexer, whichprevents the leakage of the uplink transmission signal into the unit forreceiving a downlink signal and performing the demodulation anddecoding. However, the leakage cannot be fully prevented. FIG. 13Aschematically shows the mechanism of interference in the user equipmentterminal (UE). As shown in FIG. 13A, the transmission signal generatedin the transmitter is leaked into the receiver without power of thetransmission signal being fully reduced in the Duplexer, and the leakedtransmission signal may become an interference signal which degradesquality of the reception signal.

The more separated the difference is between the frequency of the uplinktransmission signal and the frequency of the downlink reception signal,or the lower the transmission power of the uplink transmission signalis, the smaller the leakage becomes. Further the narrower the uplinktransmission bandwidth is, the smaller the leakage becomes. In uplink,the higher the path loss is, the higher the transmission power becomes.Therefore, when path loss is higher, by making the uplink transmissionbandwidth narrower, it may become possible to reduce interference of theuplink transmission signal with the downlink reception signal. FIG. 13Bschematically shows the effect caused by the interference of the uplinktransmission signal with the downlink reception signal. FIG. 13B shows atransmission signal from the user equipment terminal (UE1) with higherpath loss and a transmission signal from the user equipment terminal(UE2) with lower path loss. In other words, transmission power of UE1 ishigh and transmission power of UE2 is low.

In order to further reduce interference of the uplink transmissionsignal with the downlink reception signal, the RB allocation mode instep S809 is set to Mode-2. In the case of Mode-2, a frequency resourcewith a lower frequency is allocated to a user equipment terminal (UE)with a higher path loss. As a result, the higher transmission power ofthe user equipment terminal (UE), the more separated is the differencebetween the frequency of the uplink transmission signal and thefrequency of the downlink reception signal, and thereby interference ofthe uplink transmission signal with the downlink reception signal can bereduced. For example, in FIG. 13B, since the transmission bandwidth ofUE1 is narrow while transmission power of UE1 is high, interference withthe downlink band can be reduced. Further, in FIG. 13B, sincetransmission power of UE2 is low while the transmission bandwidth of UE2is wide, interference with the downlink band can be reduced.

In this example, it is assumed that the uplink frequency is lower thanthe downlink frequency. When the uplink frequency is higher than thedownlink frequency, Mode-3 rather than Mode-2 may be selected as the RBallocation mode in step S809.

In step S506, a Temporary RB group is determined.

The process of determining the Temporary RB group for each UL RBallocation mode is described below.

(1) If the UL RB allocation mode==Mode-0;

This process is described with reference to FIG. 14.

In step S602, it is determined whether the transmission type is High Fd.The transmission type is calculated in step S728.

When the transmission type is High Fd, RBs are allocated to the userequipment terminal (UE) among the “available RBs to be allocated to theUL-SCH to which dynamic scheduling (hereinafter called “available RBs tobe allocated”)”, which are determined in step S810, beginning from thelowest frequency or the highest frequency until the number of RBs to beallocated to the user equipment terminal (UE) is greater than or equalto N_(allocated). In this case, hopping is not used.

Specifically, in step S604, it is determined that transmission of theUL-SCH in the corresponding sub-frame is initial transmission. Whentransmission of the UL-SCH is determined as initial transmission (stepS604: YES), in step S606, the RB with the highest frequency or thelowest frequency which is far from the center of the system band isallocated among available RBs to be allocated. In other words, when theRB with the lowest frequency is far from the center of the system band,RBs are allocated to the user equipment terminal (UE) beginning from thelowest frequency until the number of RBs to be allocated to the userequipment terminal (UE) is greater than or equal to N_(allocated). Onthe other hand, when the RB with the highest frequency is far from thecenter of the system band, RBs are allocated to the user equipmentterminal (UE) beginning from the highest frequency until the number ofRBs to be allocated to the user equipment terminal (UE) is greater thanor equal to N_(allocated). When the RB with the highest frequency andthe RB with the lowest frequency have the same distance from the centerof the system band, the RB with the lowest frequency may be allocated.

On the other hand, when transmission of the UL-SCH in the correspondingsub-frame is determined as retransmission (step S604: NO), the followingprocess is performed. When the RB with the highest frequency isallocated for previous HARQ transmission, the RB with the lowestfrequency is allocated. When the RB with the lowest frequency isallocated for the previous HARQ transmission, the RB with the highestfrequency is allocated (step S608). In other words, when the RB with thehighest frequency is allocated for the previous HARQ transmission, RBsare allocated to the user equipment terminal (UE) beginning from thelowest frequency until the number of RBs to be allocated to the userequipment terminal (UE) is greater than or equal to N_(allocated). Onthe other hand, when the RB with the lowest frequency is allocated forthe previous HARQ transmission, RBs are allocated to the user equipmentterminal (UE) beginning from the highest frequency until the number ofRBs to be allocated to the user equipment terminal (UE) is greater thanor equal to N_(allocated).

Alternatively, in step S608, upon determining whether RBs are allocatedbeginning from the lowest frequency or the highest frequency, the basestation apparatus may determine as follows based on whether the RBsinclude RBs allocated to previous HARQ transmission. N_(small) denotesthe number of RBs allocated to the previous HARQ transmission, which areincluded in a set of RBs when the RBs are allocated beginning from thelowest frequency. N_(large) denotes the number of RBs allocated to theprevious HARQ transmission, which are included in a set of RBs when theRBs are allocated beginning from the highest frequency. IfN_(small)>N_(large), RBs are allocated beginning from the highestfrequency. If N_(small)=<N_(large), RBs are allocated beginning from thelowest frequency.

In this manner, in the case of a higher fading frequency of the userequipment terminal (UE), i.e., when the user equipment terminal (UE)moves fast, the approach in which RBs are allocated beginning from thelowest frequency and the approach in which RBs are allocated beginningfrom the highest frequency are switched for each HARQ transmission, andthereby frequency diversity is easily achieved. As a result,transmission properties and the system capacity can be improved.

Specifically, when frequency resources (RBs) are allocated to the sharedchannel used by plural user equipment terminals beginning from the endof the system bandwidth, the base station apparatus may allocate, to theshared channel used by the user equipment terminals, a frequencyresource (RB) which is different from a frequency resource (RB) used forprevious transmission among frequency resources (RBs) at both ends ofthe system bandwidth.

When the transmission type is Low Fd (step S602: NO), the process goesto step S610. When the transmission type is Low Fd, RBs are allocated tothe user equipment terminal (UE) among the “available RBs to beallocated to the UL-SCH to which dynamic scheduling is applied(hereinafter called “available RBs to be allocated”)”, which aredetermined in step S810, beginning from the lowest frequency or thehighest frequency until the number of RBs to be allocated to the userequipment terminal (UE) is greater than or equal to N_(allocated). Inthis case, hopping is not used. Upon determining whether RBs areallocated beginning from the lowest frequency or the highest frequency,the base station apparatus allocates RBs with higher received SIR of theSounding RS.

Specifically, the base station apparatus determines RBs as follows.

If SIR_(estimated) in the case where RBs are allocated beginning fromthe lowest frequency is higher than SIR_(estimated) in the case whereRBs are allocated beginning from the highest frequency, RBs areallocated beginning from the lowest frequency.

If SIR_(estimated) in the case where RBs are allocated beginning fromthe lowest frequency is lower than or equal to SIR_(estimated) in thecase where RBs are allocated beginning from the highest frequency, RBsare allocated beginning from the highest frequency.

For example, when the base station apparatus allocates frequencyresources (RBs) to the shared channel used by plural user equipmentterminals, beginning from the end of the system bandwidth, the basestation apparatus may allocate, to the shared channel used by the pluraluser equipment terminals, a frequency resource (RB) with higher radioquality among frequency resources (RBs) at both ends of the systembandwidth.

This process is used for both initial transmission and retransmission.

In this manner, in the case of a lower fading frequency of the userequipment terminal (UE), i.e., when the user equipment terminal (UE)moves slowly, the approach in which RBs are allocated beginning from thelowest frequency and the approach in which RBs are allocated beginningfrom the highest frequency are switched based on radio quality, andthereby higher quality transmission is easily achieved. As a result,transmission properties and the system capacity can be improved.

(2) If the UL RB allocation mode ==Mode-1;

RBs are allocated to the user equipment terminal (UE) among the“available RBs to be allocated to the UL-SCH to which dynamic schedulingis applied (hereinafter called “available RBs to be allocated”)”, whichare calculated in step S410, beginning from the lowest frequency or thehighest frequency until the number of RBs to be allocated to the userequipment terminal (UE) is greater than or equal to N_(allocated). Inthis case, hopping is not used. Upon determining whether RBs areallocated beginning from the lowest frequency or the highest frequency,the base station apparatus selects RBs far from the center of the systemband. When RBs have the same distance from the center of the systemband, the base station apparatus allocates RBs beginning from the lowestfrequency.

(3) If the UL RB allocation mode ==Mode-2;

RBs are allocated to the user equipment terminal (UE) among the“available RBs to be allocated to the UL-SCH to which dynamic schedulingis applied (hereinafter called “available RBs to be allocated”)”, whichare calculated in step S810, beginning from the lowest frequency untilthe number of RBs to be allocated to the user equipment terminal (UE) isgreater than or equal to N_(allocated). In this case, hopping is notused.

(4) If the UL RB allocation mode is anything other than Mode-0, Mode-1,and Mode-2; RBs are allocated to the user equipment terminal (UE) amongthe “available RBs to be allocated to the UL-SCH to which dynamicscheduling is applied (hereinafter called “available RBs to beallocated”)”, which are calculated in step S810, beginning from thehighest frequency until the number of RBs to be allocated to the userequipment terminal (UE) is greater than or equal to N_(allocated). Inthis case, hopping is not used.

In this process (step S506), a set of RBs “to be allocated to the userequipment terminals (UE)” is called a Temporary RB group.

In the following process, it is assumed that Num_(RB)=N_(allocated).

When the user equipment terminal performs retransmission of the UL-SCHand when the Uplink Scheduling Grant for retransmission is notspecified, this process is not performed. Instead, the base stationapparatus allocates, to the UL-SCH for retransmission, the same RBs asthe RBs used for the previous transmission.

In step S508, the base station apparatus determines whether the userequipment terminal (UE) transmits the UL-SCH for initial transmission.When the user equipment terminal (UE) transmits the UL-SCH for initialtransmission (step S508: YES), the process goes to step S510. When theuser equipment terminal (UE) does not transmit the UL-SCH for initialtransmission (step S508: NO), the process goes to step S530.

In step S510, the base station apparatus selects the MCS for the userequipment terminal (UE). For example, the base station apparatus 200calculates path loss (Pathloss) between the base station apparatus 200and the user equipment terminal (UE), and then selects the MCS based onthe path loss (Pathloss) referring to the look-up table as shown in FIG.15. In the following descriptions, the selected MCS is defined asMCS_(tmp). It should be noted that FIG. 15 merely shows example valuesand values other than those shown in FIG. 15 may be used.

Alternatively, the base station apparatus 200 may select the MCS basedon “Pathloss+Sounding SIR−Target SIR” rather than the path loss(Pathloss). The Sounding SIR refers to the received SIR of the SoundingReference Signal and the Target SIR refers to a target SIR of theSounding Reference Signal. In this manner, in consideration of thereceived SIR of the Sounding Reference Signal in addition to the pathloss (Pathloss), the base station apparatus can select the MCS inaccordance with instantaneous fluctuations of the propagationenvironment, such as fluctuations by Rayleigh fading.

When the base station apparatus cannot calculate the path loss(Pathloss) for the user equipment terminal (UE) at the start ofcommunications or immediately after handover, MCS_(tmp) may bedetermined as MCS_(REF) (MCS_(tmp)=MCS_(REF)). MCS_(REF) may be storedas internal data in the base station apparatus or may be designated viathe external server or the like.

For example, the path loss (Pathloss) may be the path loss (Pathloss)reported from the user equipment terminal (UE). The path loss (Pathloss)is calculated as follows based on transmission power of the downlinkreference signal and reception power of the downlink reference signal inthe user equipment terminal (UE).

Pathloss=(transmission power of the downlink referencesignal)−(reception power of the downlink reference signal)

Alternatively, the path loss (Pathloss) may be calculated based on UPH(UE Power Headroom) reported from the user equipment terminal (UE). Inthis case, the path loss (Pathloss) is calculated as follows. It isassumed that the UPH is calculated based on transmission power of thePUSCH. It should be noted that reception power of the PUSCH may bereception power of the Demodulation Reference Signal via the PUSCH.

Pathloss=maximum transmission power of the UE−UPH−reception power of thePUSCH

Alternatively, the path loss (Pathloss) may be calculated based ontransmission power of the Uplink Shared Channel, which is reported bythe user equipment terminal (UE). In this case, the path loss (Pathloss)is calculated as follows.

Pathloss=transmission power of the PUSCH−reception power of the PUSCH

Alternatively, the path loss (Pathloss) may be calculated based on thefollowing equations.

UPH=maximum transmission power of the UE−transmission power of the UE

$\begin{matrix}\left\lbrack {{Equation}\mspace{14mu} 21} \right\rbrack & \; \\{{PL} = \frac{\begin{matrix}{{Max\_ power} - {UPH} - {10 \cdot {\log \left( B_{{data},{tmp}} \right)}} -} \\{P_{O\; \_ \; {PUSCH}} - {\Delta_{MCS}\left( {MCS}_{tmp} \right)} + {f(i)}}\end{matrix}}{\alpha}} & \;\end{matrix}$

where MAX_power is the maximum transmission power of the user equipmentterminal (UE) and transmission power of the user equipment terminal (UE)corresponds to Txpow in the following equation ([Equation 22]).

Next, in step S512, power offset to be transmitted to the user equipmentterminal (UE) is calculated. Typically, transmission power of the UplinkShared Channel in the E-UTRA system is calculated according to thefollowing equation (see 3GPP 36.213).

P _(PUSCH)(i)=min{P _(MAX),10 log₁₀(M _(PUSCH)(i))+P _(O) _(—)_(PUSCH)(j)+α·PL+Δ _(MCS)(MCS(i))+f(i)}  [Equation 22]

P_(USCH)(i): transmission power of the PUSCH in the sub-frame #i

P_(MAX): maximum transmission power of the UE

M_(PUSCH): the number of RBs

P_(O) _(—) _(PUSCH): a parameter specified by the network (NW)

α: a parameter specified by the network (NW)

PL: path loss (Pathloss)

Δ_(MCS): an offset value determined for each MCS

f(i): an offset value for adjustment

f(i)=f(i−1)+Δ

In step S512, the value of Δ is calculated. Specifically, the TPCcommand (Δ) to be transmitted to the user equipment terminal (UE) bymeans of the UL Scheduling Grant is calculated. In the following, theoffset value to be transmitted to the user equipment terminal (UE) isdefined as Δ.

In step S512, the value of Δ is determined by means of the offset basedon the priority level of the logical channel group with the highestpriority level. The subscript LCG refers to the logical channel group.

Δ=Δ_(LCG)

For example, the base station apparatus 200 increases the value ofΔ_(LCG) for the logical channel group to be transmitted with highquality and with the high priority level, thereby increasing thereceived SIR. As a result, the error rate can be reduced. In thismanner, the base station apparatus 200 can adjust the offset value basedon the priority level, the logical channel, or the logical channel groupto adjust the error rate.

Next, the value of Δ is adjusted as follows, based on SIR_offset whichis calculated according to the offset adjustment process in anouter-loop manner.

Δ=Δ+SIR_offset

SIR_offset is calculated as follows in the outer-loop manner.

SIR_Offset is adjusted in the outer-loop manner based on both the CRCresult of the UL-SCH in which the priority level of the logical channelgroup with the highest priority level is Z_adjust and the followingequation. SIR_offset is not adjusted in the outer-loop manner, when thepriority level of the logical channel group with the highest prioritylevel is different from Z_(adjust).

$\begin{matrix}\left\lbrack {{Equation}\mspace{14mu} 23} \right\rbrack & \; \\{{SIR\_ offset} = \left\{ \begin{matrix}{{SIR\_ offset} - {\Delta_{adj} \times {BLER}_{target}^{({LCG}_{Z})}}} & {{Input} = {\,{``{ACK}"}}} \\\begin{matrix}{{SIR\_ offset} + {\Delta_{adj} \times}} \\\left( {1 - {BLER}_{target}^{({LCG}_{Z})}} \right)\end{matrix} & {{Input} = {\,{``{NACK}"}}} \\{SIR\_ offset} & {{Input} = {\,{``{DTX}"}}}\end{matrix} \right.} & \;\end{matrix}$

This equation is explained below in detail. When the CRC result is theACK, SIR_offset is slightly decreased based on this equation. In otherwords, increase in the unnecessary received level can be avoided bydecreasing transmission power in the user equipment terminal (UE). Onthe other hand, when the CRC result is the NACK, SIR_offset is increasedbased on this equation. In other words, the error rate can be reduced byincreasing transmission power in the user equipment terminal (UE) andimproving the received SIR. In the case of DTX, since the user equipmentterminal (UE) cannot successfully receive the UL Scheduling Grant,SIR_offset is not adjusted. In this manner, uplink transmission power isadjusted based on the ACK or the NACK and the range of increase ordecrease for setting transmission power is determined according to thetarget error rate, and thereby the error rate of the UL-SCH can bebrought close to the target error rate.

For example, if a required target error rate BLER_target^((LCG))=0.1 andΔ_(adj)=0.5, then SIR_offset=SIR_offset−0.05 dB in the case of the ACKand SIR_offset=SIR_offset+0.45 dB in the case of the NACK. After awhile, the ratio of the ACK becomes equal to 90% and the ratio of theNACK becomes equal to 10%. As a result, the value of SIR_offset does notchange. In this manner, adjusting SIR_offset according to this equationallows the error rate to converge on the target error rate BLER_(target)^((LCG)).

Since the base station apparatus 200 cannot identify the logical channelincluded in data (MAC PDU) which are mapped to the uplink shared channeluntil the CRC result is OK, the logical channel group with highestpriority in step S730 is used as the “logical channel group with highestpriority”. It should be noted that SIR_offset is adjusted for each userequipment terminal (UE) and that the priority level Z_(adjust) of thelogical channel group in this process is designated via the externalinterface (I/F) for each user equipment terminal (UE).

In this manner, adjusting the offset in the outer-loop manner withrespect to one predetermined logical channel group rather than withrespect to all the logical channel groups allows for the reduction ofthe workload in the base station apparatus. For example, the prioritylevel of a logical channel group with the highest frequency oftransmission occurrences (with the largest number of transmissionoccurrences in a unit of time) is set as the priority level Z_(adjust)of the logical channel group.

It should be noted that Δ_(adj), BLER_(target) ^((LGCz)) can bedesignated via the external interface (I/F). The maximum value ofSIR_offset is defined as SIR_offset_(max) and the minimum value ofSIR_offset is defined as SIR_offset_(min). When SIR_offset iscontinuously determined as the maximum value or the minimum value, theabove-mentioned calculation is not performed.

Then, the base station apparatus compares the final value of Δ with thevalue of f(i) retained by the user equipment terminal (UE) and transmitsto the user equipment terminal (UE) the TPC command which is closest tothe value of “Δ−f(i)” by means of the UL Scheduling Grant in thecorresponding sub-frame. The base station apparatus 200 may assume thatthe error rate of the TPC command is equal to zero (0) and estimate thevalue of f(i) retained by the user equipment terminal (UE).

This example assumes the use of the Accummulated TPC command. However,the Absolute TPC command can be used to calculate the TPC command in asimilar manner.

Although the offset adjustment process in the outer-loop manner isperformed only when the priority level of the logical channel group withthe highest priority level is Z_(adjust), the process of“Δ=Δ+SIR_offset” is performed regardless of whether the priority levelof the logical channel group with the highest priority level isZ_(adjust). The adjustment of the error rate based on the logicalchannel group is performed by the offset process based on the prioritylevel.

Next, in steps S514 and S516, the correction process of the allocationbandwidth based on UPH is performed.

In step S514, the number of RBs in the Temporary RB group is defined asB_(data,tmp). Then, the estimated value of transmission power of theuser equipment terminal (UE) is calculated according to the followingequation ([Equation 24]).

Txpow=10*log₁₀ B _(data,tmp) +P _(O) _(—) _(PUSCH)α×Δ_(MCS)(MCS_(tmp))+f(i)

P_(O) _(—) _(PUSCH): a parameter specified by the network (NW) (see 3GPP36.213)

f(i): the combination (sum) of TPC commands which have been transmitteduntil the corresponding sub-frame.

PL: path loss (Pathloss), which is estimated based on UPH and thereceived level of the Demodulation RS.

In step S514, it is determined whether Txpow is higher than P_(max).P_(max) denotes maximum transmission power of the user equipmentterminal (UE). When Txpow is higher than P_(max) (step S514: YES), theprocess goes to step S516. Otherwise (step S514: NO), the process goesto step S518.

In step S516, B_(data,tmp) is defined as follows.

$\begin{matrix}\left\lbrack {{Equation}\mspace{14mu} 25} \right\rbrack & \; \\{B_{{data},{tmp}} = {\max\left( {1,{{floor}\left( 10^{\frac{P_{\max} - {(\begin{matrix}{P_{O\; \_ \mspace{11mu} {PUSCH}} + {\alpha \times {PL}} +} \\{{\Delta_{MCS}{({MCS}_{tmp})}} + {f{(i)}}}\end{matrix})}}{10}} \right)}} \right)}} & \;\end{matrix}$

Also, B_(data,tmp) is defined as “the number of RBs Num_(RB) to beallocated”. Then, RBs in the Temporary RB group are removed, such thatthe number of RBs to be allocated to the user equipment terminal (UE) isnot less than Num_(RB), and the number of subcarriers includes onlyfactors of 2, 3, and 5. In this equation, Maximum Power Reduction in theuser equipment terminal (UE) may or may not be taken into consideration.

Upon allocation of the Temporary RB group in step S506, when RBs areallocated beginning from the highest frequency, RBs are removedbeginning from the lowest frequency. On the other hand, when RBs areallocated beginning from the lowest frequency, RBs are removed beginningfrom the highest frequency.

Next, in steps S518 and S520, the correction process of the allocationbandwidth based on N_(max,bit) is performed.

In step S518, the number of RBs (Num_(RB)) in the Temporary RB group iscalculated and also the MAC PDU size (hereinafter called Size) iscalculated. Then, it is determined whether Size is greater thanN_(max,bit) (Size>N_(max,bit)).

When it is determined that Size is greater than N_(max,bit)(Size>N_(max,bit)) (step S518: YES), RBs in the Temporary RB group areremoved until Size is less than or equal to N_(max,bit)(Size=<N_(max,bit)) in step S520. Upon allocation of the Temporary RBgroup, when RBs are allocated beginning from the highest frequency, RBsare removed beginning from the lowest frequency. On the other hand, whenRBs are allocated beginning from the lowest frequency, RBs are removedbeginning from the highest frequency.

On the other hand, when it is determined that Size is less than or equalto N_(max,bit) (Size=<N_(max,bit)) (step S518: YES), the process goes tostep S522.

In steps S522 and S524, the correction process of the allocationbandwidth based on the amount of data in the buffer is performed.Specifically, the number of RBs to be allocated to the user equipmentterminal (UE) is recalculated based on the comparison between the amountof data in the UL Buffer and the Size. Please refer to steps S730 andS732 in step S204 for the process of estimating the amount of data inthe UL Buffer.

When the base station apparatus receives from the user equipmentterminal (UE) “allocation request for the UL-SCH: REQUESTING” by meansof the Scheduling request and uplink resources (resources for theUL-SCH) have not been allocated to the user equipment terminal (UE)since the base station apparatus has received the Scheduling request,the following process “in the case of enough data” (step S522: YES) isperformed.

Specifically, in step S522, it is determined whether there are enoughdata in the RLC Buffer according to the following equation ([Equation26]). α^(TFRS) is a coefficient input by the external interface (I/F).

$\begin{matrix}\left\lbrack {{Equation}\mspace{14mu} 26} \right\rbrack & \; \\{{{Size} \leq \alpha_{ULTFRS}}{\cdot {\sum\limits_{LCG}{{Buffer}_{LCG}\text{:}\mspace{14mu} {in}\mspace{14mu} {the}\mspace{14mu} {case}\mspace{14mu} {of}\mspace{14mu} {enough}\mspace{14mu} {data}}}}{{Size} > {\alpha_{ULTFRS} \cdot {\sum\limits_{LCG}{{Buffer}_{LCG}\text{:}\mspace{14mu} {in}\mspace{14mu} {the}\mspace{14mu} {case}\mspace{14mu} {of}\mspace{14mu} {not}\mspace{14mu} {enough}\mspace{14mu} {data}}}}}} & \;\end{matrix}$

When it is determined that there are enough data in the RLC Buffer (stepS522: YES), the process goes to step S526. In this case, all the RBs inthe Temporary RB group are to be allocated to the user equipmentterminal (UE).

On the other hand, when it is determined that there are not enough datain the RLC Buffer (step S522: NO), the process goes to step S524.

In step S524, the number of RBs Num_(RB) to be allocated is recalculatedbased on

$\alpha_{TFRS}{\cdot {\sum\limits_{LCG}{Buffer}_{LCG}}}$

(hereinafter called Size_(buffer)) and MCS_(tmp).

When the number of subcarriers corresponding to Num_(RB) includesfactors other than 2, 3, and 5, Num_(RB) is determined as a minimuminteger among integers which include only factors of 2, 3, and 5 for thenumber of subcarriers and which are greater than Num_(RB). RBs in theTemporary RB group are removed, such that the number of RBs to beallocated to the user equipment terminal (UE) is not less than Num_(RB).Upon allocation of the Temporary RB group, when RBs are allocatedbeginning from the highest frequency, RBs are removed beginning from thelowest frequency. On the other hand, when RBs are allocated beginningfrom the lowest frequency. RBs are removed beginning from the highestfrequency.

In step S526, the Temporary RB group after the processes of stepsS514-S524 is determined as the RBs to be allocated to the user equipmentterminal (UE) in the corresponding sub-frame.

In step S528, the base station apparatus generates the UL SchedulingGrant to be transmitted to the user equipment terminal (UE) based onboth MCS_(tmp) and (the group of) RBs determined in step S526.Specifically, the base station apparatus determines the transmissionformat of the UL-SCH.

On the other hand, when the user equipment terminal (UE) does nottransmit the UL-SCH for initial transmission in step S508, in otherwords, when the user equipment terminal (UE) transmits the UL-SCH forretransmission (step S508: NO), the process goes to step S530.

In step S530, the number of RBs for retransmission is determined aseither the number of RBs for initial transmission or the number of RBsin the Temporary RB group, whichever is smaller. When the number of RBsfor initial transmission is less than the number of RBs in the TemporaryRB group, RBs in the Temporary RB group are removed until the number ofRBs to be allocated to the user equipment terminal (UE) is the same asthe number of RBs for initial transmission. Upon allocation of theTemporary RB group, when RBs are allocated beginning from the highestfrequency, RBs are removed beginning from the lowest frequency. On theother hand, when RBs are allocated beginning from the lowest frequency,RBs are removed beginning from the highest frequency.

In step S532, the TPC command to be transmitted to the user equipmentterminal (UE) by means of the UL Scheduling Grant is determined.

Δ=Δ_(LCG) SIR_offset+Δ_(LCG) ^((HARQ))

The offset value Δ_(LCG) ^((HARQ)) is designated via the externalinterface (I/F) for each logical channel group. Upon retransmission,“the process in the outer-loop manner”, which is described in step S512,is also performed.

In this manner, the base station apparatus notifies the user equipmentterminal (UE) of a larger power offset for retransmission, therebyreducing the error rate for retransmission.

In step S534, the base station apparatus generates the UL SchedulingGrant to be transmitted to the user equipment terminal (UE). Regardingfrequency resources, the base station apparatus notifies the userequipment terminal (UE) of the resource blocks determined in step S530.The MCS for retransmission may be the same as the MCS for initialtransmission. Alternatively, the modulation scheme for retransmissionmay be the same as the modulation scheme for initial transmission.

Although the UL Scheduling Grant is specified for retransmission insteps S530, S532, and S534, these steps may be omitted when the ULScheduling Grant is not specified for retransmission. It should be notedthat frequency resources to be used by the user equipment terminal (UE)are reserved even when the UL Scheduling Grant is not specified.

In step S816, the value of “j” is incremented by one. In step S818, itis determined whether the value of “j” is less than or equal toN_(UL-SCH). If the value of “j” is less than or equal to N_(UL-SCH)(step S818: YES), the process returns to step S810. Otherwise (stepS818: NO), the process comes to an end.

As described above, the base station apparatus transmits the TPC commandto the user equipment terminal (UE) by means of the UL Scheduling Grantin steps S512 and S532. The process of transmitting the TPC command bymeans of the UL Scheduling Grant may be combined with the process ofperiodically transmitting the TPC command in the sub-frame in which theUL Scheduling Grant is not transmitted.

In the following, an example of periodically transmitting the TPCcommand in the sub-frame in which the UL Scheduling Grant is nottransmitted.

The base station apparatus 200 calculates the TPC command based on thereceived SIR of the Sounding RS, upon periodically transmitting the TPCcommand to the user equipment terminal (UE). Specifically, the basestation apparatus determines a target SIR (Target_SIR) and calculatesΔ_(Sounding) according to the following equation.

Δ_(Sounding)=Target_(—) SIR−SIR _(Sounding)

Then, the base station apparatus transmits the TPC command which isclosest to Δ_(Sounding). The TPC command is transmitted as a part of thePDCCH.

With reference to FIG. 11B, another embodiment of the UL TFR selectionin step S814 is described below. The embodiment shown in FIG. 11B is thesame as the embodiment shown in FIG. 11A except for steps S510, S512,and S532, and thus only these steps are described below. Steps S504A,S505A, S506A, S508A, S514A, S516A, S518A, S520A, S522A, S524A, S526A,S528A, S530A, and S534A in FIG. 11B are the same as steps S504, S505,S506, S508, S514, S516, S518, S520, S522, S524, S526, S528, S530, andS534, respectively, in FIG. 11A. Their discussion is thus omitted.

In step S509A, the value of Δ in the [Equation 22] is calculated.Specifically, the TPC command (Δ) to be transmitted to the userequipment terminal (UE) by means of the UL Scheduling Grant iscalculated. In the following, the offset value to be transmitted to theuser equipment terminal (UE) is defined as Δ.

Δ is calculated according to the following equation based on thereceived SIR (R_SIR) of the Sounding RS and the target SIR (T_SIR) ofthe Sounding RS.

Δ=T _(—) SIR−R _(—) SIR

Next, in step S510A, the MCS (Modulation and Coding Scheme) for theUplink Shared Channel to be used for transmission by the user equipmentterminal (UE) is selected. For example, an expected SIR (SIR_Expected)for the Uplink Shared Channel may be calculated based on the receivedSIR of the Sounding Reference Signal, and then the MCS (specifically,the data size, the modulation scheme, and the coding rate) may becalculated based on SIR_Expected and TF_Related table as shown in FIGS.12A and 12B. It should be noted that the coding rate is uniquelycalculated based on the data size, the modulation scheme, and the numberof RBs.

Next, an example of calculating SIR_Expected is described below.Typically, transmission power of the Sounding Reference Signal in theE-UTRA system is calculated according to the following equation([Equation 28]) (see 3GPP 36.213).

P _(SRS)(i)=min{P _(MAX) ,P _(SRS) _(—) _(OFFSET)+10 log₁₀(M _(SRS))+P_(O) _(—) _(PUSCH) +α·PL+Δ _(MCS)(MCS _(REF))+f(i)}  [Equation 28]

P_(SRS)(i): transmission power of the Sounding Reference Signal in thesub-frame #i

P_(MAX): maximum transmission power of the UE

P_(SRS) _(—) _(OFFSET): a power offset between the Uplink Shared Channeland the Sounding Reference Signal

M_(SRS): the number of RBs for the Sounding Reference Signal

P_(O) _(—) _(PUSCH): a parameter specified by the network (NW)

α: a parameter specified by the network (NW)

PL: path loss (Pathloss)

Δ_(MCS): an offset value determined for each MCS

MCS_(REF): the MCS for the reference signal

f(i): an offset value for adjustment

f(i)=f(i−1)+Δ

P_(O) _(—) _(PUSCH), α, PL, f(i) in the [Equation 28] are the same asthose in the [Equation 22]. Assuming that Δ_(MCS) in the [Equation 22]and [Equation 28] is equal to zero (0), transmission power of the PUSCHfor each RB is calculated as follows.

P _(PUSCH)(i)=P _(SRS) −P _(SRS) _(—) _(OFFSET)

Assuming that interference power in the Sounding Reference Signal is thesame as interference power in the reference signal of the Uplink SharedChannel, SIR_Expected is calculated as follows.

SIR_Expected=R _(—) SIR−P _(SRS) _(—) _(OFFSET)

As described above, R_SIR is the received SIR of the Sounding ReferenceSignal.

P_(SRS) _(—) _(OFFSET), which is defined as a power offset between theUplink Shared Channel and the Sounding Reference Signal, may becontrolled at relatively longer intervals based on path loss between theuser equipment terminal and the base station apparatus. For example, asshown in FIG. 11C, the value of P_(SRS) _(—) _(OFFSET) may be definedbased on path loss. According to the change in path loss, the value ofP_(SRS) _(—) _(OFFSET) may be changed with reference to FIG. 11C. Thevalue of P_(SRS) _(—) _(OFFSET) may be transmitted to the user equipmentterminal (UE) by means of RRC signaling. Please refer to step S510 forthe calculation of path loss.

SIR_Expected may be further adjusted in the outer-loop manner asfollows.

SIR_Expected=SIR_Expected+SIR_Offset

In this case, the MCS is selected based on SIR_Expected after thisadjustment. SIR_Offset may be calculated according to the equation (10)([Equation 11]).

SIR_offset may be calculated based on the CRC result of the UL-SCH inwhich the priority level of the logical channel group with the highestpriority level is Z_(adjust). When the priority level of the logicalchannel group with the highest priority level is different fromZ_(adjust), SIR_offset may not be adjusted in the outer-loop manner.

The equation (10) ([Equation 11]) is explained below in detail. When theCRC result is the ACK, SIR_offset is slightly increased based on thisequation. In other words, throughput can be increased by raising the MCSlevel. On the other hand, when the CRC result is the NACK, SIR_offset isdecreased based on this equation. In other words, the error rate can bereduced by lowering the MCS level and reducing the required SIR. In thecase of DTX, since the user equipment terminal (UE) cannot successfullyreceive the UL Scheduling Grant, SIR_offset is not adjusted. In thismanner, radio quality of the Uplink Shared Channel (SIR_Expected),namely, the MCS level is adjusted based on the ACK or the NACK and therange of increase or decrease for setting the MCS level is determinedaccording to the target error rate, and thereby the error rate of theUL-SCH can be brought close to the target error rate.

For example, if a required target error rate BLER_(target) ^((LCG))=0.1and Δ_(adj)=0.5, then SIR_offset=SIR_offset+0.05 dB in the case of theACK and SIR_offset=SIR_offset−0.45 dB in the case of the NACK. After awhile, the ratio of the ACK becomes equal to 90% and the ratio of theNACK becomes equal to 10%. As a result, the value of SIR_offset does notchange. In this manner, adjusting SIR_offset according to theabove-mentioned equation allows the error rate to converge on the targeterror rate BLER_(target) ^((LCG)).

Since the base station apparatus 200 cannot identify the logical channelincluded in data (MAC PDU) which are mapped to the Uplink Shared Channel(UL-SCH) until the CRC result is OK, the logical channel group with thehighest priority level in step S730 is used as the “logical channelgroup with the highest priority level”. It should be noted thatSIR_offset is adjusted for each user equipment terminal (UE) and thatthe priority level Z_(adjust) of the logical channel group in thisprocess is designated via the external interface (I/F) for each userequipment terminal (UE).

In this manner, adjusting the offset in the outer-loop manner withrespect to one predetermined logical channel group rather than withrespect to all the logical channel groups allows for the reduction ofthe workload in the base station apparatus. For example, the prioritylevel of a logical channel group with the highest frequency oftransmission occurrences (with the largest number of transmissionoccurrences in a unit of time) is set as the priority level Z_(adjust)of the logical channel group.

It should be noted that Δ_(adj), BLER_(target) ^((LGCz)) can bedesignated via the external interface (I/F). The maximum value ofSIR_offset is defined as SIR_offset_(max) and the minimum value ofSIR_offset is defined as SIR_offset_(min). When SIR_offset iscontinuously determined as the maximum value or the minimum value, theabove-mentioned calculation is not performed.

Alternatively, P_(SRS) _(—) _(OFFSET) in the [Equation 28] rather thanSIR_Expected may be adjusted according to the following equation.

P _(SRS) _(—) _(OFFSET) =P _(SRS) _(—) _(OFFSET) SIR_Offset

Alternatively, P_(O) _(—) _(USCH)(i) in the [Equation 22] rather thanSIR_Expected may be adjusted according to the following equation.

P _(O) _(—) _(USCH)(i)=P _(O) _(—) _(USCH)(i)+SIR_Offset

In this case, SIR_offset is adjusted according to the ([Equation 23]).

In step S511A, the MCS is reselected based on the priority level.Specifically, SIR_Expected in step S510A is recalculated by the offsetΔ_(LCG) based on the priority level of the logical channel group withthe highest priority level. Then, the MCS is reselected based on therecalculated SIR_Expected with reference to FIGS. 12A and 12B. Morespecifically, SIR_Expected is recalculated according to the followingequation.

SIR_Expected=SIR_Expected−Δ_(LCG)

The subscript LCG refers to the logical channel group. For example, thebase station apparatus 200 increases the value of Δ_(LCG) for thelogical channel group to be transmitted with high quality and with thehigh priority level, thereby lowering the MCS level. As a result, theerror rate can be reduced. In this manner, the base station apparatus200 can adjust the offset value based on the priority level, the logicalchannel, or the logical channel group to adjust the error rate.

In step S532A, the TPC command to be transmitted to the user equipmentterminal (UE) by means of the UL Scheduling Grant is determined.

Δ=T _(—) SIR−R _(—) SIR+Δ _(LCG) ^((HARQ))

The offset value Δ_(LCG) ^((HARQ)) is designated via the externalinterface (I/F) for each logical channel group. In this manner, the basestation apparatus notifies the user equipment terminal (UE) of a largerpower offset for retransmission, thereby reducing the error rate forretransmission.

Next, the base station apparatus 200 according to an embodiment of thepresent invention is described with reference to FIG. 16.

As shown in FIG. 16, the base station apparatus 200 according to anembodiment of the present invention includes a layer 1 processing unit202, a user equipment status management unit 204, a schedulingcoefficient calculation unit 206, a UE selection unit 208, a TFR(Transport Format and Resource block) Selection unit 210, an other-CHresource management unit 212, a frequency resource management unit 214,a persistent resource management unit 216, and a UE Buffer estimationunit 218. The UE Buffer estimation unit 218 includes UE Buff_(1,1), UEBuff_(1,2), UE Buff_(1,k), UE Buff_(2,1), UE Buff_(2,2), . . . , UEBuff_(2,k), and, UE Buff_(n,1), UE Buff_(n,k) corresponding to a logicalchannel group #1, a logical channel group a logical channel group #k forUE #1, a logical channel group #1, a logical channel group a logicalchannel group #k for UE #2, a logical channel group #1, a logicalchannel group a logical channel group #k for UE #n, respectively. The UEBuff_(1,k) estimates the amount of data in the UE buffer based on theBuffer Status Report reported from the user equipment terminal (UE)rather than actually performing data buffering.

In FIG. 16, the base station apparatus 200 includes the UE Buff_(n,k)corresponding to the logical channel group #k for the UE #n with respectto each user equipment terminal and each logical channel group.Alternatively, the base station apparatus 200 may include one UE Bufferestimation unit for all the user equipment terminals (UEs) or pluraluser equipment terminals (UEs). Alternatively, the base stationapparatus 200 may include one UE Buffer estimation unit with respect toeach user equipment terminal (UE) and may not include one UE Bufferestimation unit with respect to each logical channel group.

The layer 1 processing unit 202 performs processes related to the layer1. More specifically, the layer 1 processing unit 202 performs, forexample, a channel coding process and an IFFT process on the sharedchannel transmitted in downlink and a reception process such as an FFTprocess and a channel decoding process on the shared channel transmittedin uplink.

Further, the layer 1 processing unit 202 performs transmission of theDownlink Scheduling Information and the Uplink Scheduling Grant. TheDownlink Scheduling Information is control information for the DownlinkShared Channel (DL-SCH) and the Uplink Scheduling Grant is controlinformation for the Uplink Shared Channel (UL-SCH).

Further, the layer 1 processing unit 202 performs reception of controlinformation transmitted in uplink, i.e., CQI (Channel QualityInformation) and acknowledgement information with respect to theDownlink Shared Channel (DL-SCH). The CQI and the acknowledgementinformation are transmitted to the user equipment status management unit204.

Further, the layer 1 processing unit 202 detects the uplinksynchronization state based on the Sounding Reference Signal transmittedin uplink and the CQI signal and reports the detection result to theuser equipment status management unit 204. Further, the layer 1processing unit 202 measures the SIR of the Sounding Reference Signaltransmitted in uplink and reports the measurement result to the userequipment status management unit 204. For example, the SIR of theSounding Reference Signal is used in step S732.

Further, the layer 1 processing unit 202 may estimate uplink receptiontimings based on the Sounding Reference Signal transmitted in uplink andthe CQI signal.

Further, the layer 1 processing unit 202 may determine whether theUplink Shared Channel (UL-SCH) is actually transmitted. For example, thedetermination result is used in step 706.

Further, the layer 1 processing unit 202 may estimate path loss andreport the path loss to the user equipment status management unit 204.For example, the path loss may be used in step S814 (UL TFR Selection).

Further, the layer 1 processing unit 202 is connected to a radiointerface. More specifically, in downlink, the baseband signal generatedin the layer 1 processing unit 202 is converted into a signal in theradio frequency band. Then the converted signal is amplified in theamplifier and transmitted to the user equipment terminal (UE) via anantenna. On the other hand, in uplink, a radio frequency signal receivedby the antenna is amplified in the amplifier, frequency-converted into abaseband signal, and is input to the layer 1 processing unit 202.

The user equipment status management unit 204 performs status managementof each user equipment terminal (UE). For example, the user equipmentstatus management unit 204 performs status management of HARQ Entity inuplink, management and control of mobility of UE, management of the DRXstatus and uplink synchronization, management of whether Persistentscheduling is to be applied, management of whether a MAC Control Blockis to be transmitted, management of the transmission status, andestimation of a buffer status in the user equipment terminal (UE).Further, in step S732, the user equipment status management unit 204calculates metrics necessary for the calculation of the schedulingcoefficients and determines whether the scheduling coefficients are tobe calculated. Namely the user equipment status management unit 204performs the processes in steps S702 through S730 in FIG. 7B.

The mobility of the user equipment terminal (UE) refers to a handoverswitching a cell in which the user equipment terminal (UE) is to be incommunication. The handover includes handover at the same frequency,between different frequencies, and between different systems. In thecases of the handover between different frequencies or between differentsystems, the management and control of the Measurement Gap is includedin the management and control of mobility of the user equipment terminal(UE).

Further, the user equipment status management unit 204 performs theprocesses of steps S202 and S204. More specifically, the user equipmentstatus management unit 204 sets the maximum multiplexing number per asub-frame with respect to the UL MAC in the corresponding sub-frame, andcounts the number of user equipment terminals (UEs) which performretransmission in the corresponding sub-frame.

Further, the user equipment status management unit 204 may performperiodic calculation and transmission processes of the TPC command basedon the SIR of the Sounding RS.

The scheduling coefficient calculation unit 206 performs the processesof steps S701 and S732 through S740 in FIG. 7B. More specifically, thescheduling coefficient calculation unit 206 calculates the schedulingcoefficients of the user equipment terminals (UEs) in the correspondingsub-frame (see [Equation 14]). Then, the UE selection unit 208 selectsthe user equipment terminals (UEs) (for initial transmission) to whichradio resources are to be allocated according to dynamic schedulingbased on the calculated scheduling coefficients. The UE selection unit208 reports the number of the user equipment terminals (UEs)“N_(UL-SCH)” to which radio resources are to be allocated according todynamic scheduling to the TFR (Transport Format and Resource block)Selection unit 210.

The TFR Selection unit 210 performs the processes of steps S809, S810,S812, S814, S816, and S818. More specifically, the TFR Selection unit210 determines the transmission format related to the Uplink SharedChannel (UL-SCH) to which dynamic scheduling is applied and controlstransmission power in uplink. Information about the transmission formatand radio resources related to the Uplink Shared Channel (UL-SCH) towhich dynamic scheduling is applied determined by the TFR Selection unit210 is transmitted to the layer 1 processing unit 202 to be used fortransmission of the UL Scheduling Grant and reception of the UplinkShared Channel (UL-SCH) in the layer 1 processing unit 202.

The other-CH resource management unit 212 determines the transmissionformats and allocates radio resources for the PRACH, the PUCCH, theGuard RBs, and the RACH Message-3. The other-CH resource management unit212 reports the frequency resources among the radio resources to thefrequency resource management unit 214. Information about thetransmission formats and allocated radio resources determined by theother-CH resource management unit 212 is transmitted to the layer 1processing unit 202 via the frequency resource management unit 214 andthe TFR Selection unit 210, so that layer 1 reception processes of thePRACH, the PUCCH, and the PRACH Message-3 and transmission process ofthe PRACH Message-2 are performed in the layer 1 processing unit 202.

The frequency resource management unit 214 is connected to the TFRSelection unit 210, the other-CH resource management unit 212, and thepersistent resource management unit 216 and performs management offrequency resources. More specifically, the frequency resourcemanagement unit 214 monitors remaining frequency resources available forthe Uplink Shared Channel (UL-SCH) to which dynamic scheduling isapplied and provides information necessary for the process of step S810to the TFR Selection unit 210.

The persistent resource management unit 216 performs status managementof the uplink shared channel (UL-SCH) to which persistent scheduling isapplied and manages radio resources. More specifically, the persistentresource management unit 216 determines the transmission format relatedto the Uplink Shared Channel (UL-SCH) to which persistent scheduling isapplied and manages the radio resources. Then, the persistent resourcemanagement unit 216 reports the frequency resources among the radioresources to the frequency resource management unit 214. Informationabout the transmission format and allocated radio resources determinedby the persistent resource management unit 216 is transmitted to thelayer 1 processing unit 202 via the frequency resource management unit214 and the TFR Selection unit 210, so that the layer 1 receptionprocess of the Uplink Shared Channel (UL-SCH) to which persistentscheduling is applied is performed in the layer 1 processing unit 202.

Further, the persistent resource management unit 216 sends informationnecessary to perform the processes of steps S702 through S705 to theuser equipment status management unit 204.

The UE Buffer estimation unit 218 estimates the buffer status for eachlogical channel group in the user equipment terminal (UE), i.e., theamount of data in the buffer based on the Buffer Status Report reportedfrom the user equipment terminal (UE). More specifically, the UE Bufferestimation unit 218 performs the processes related to the UE Buffer insteps S730 and S732.

The present invention is described above by referring to specificembodiments. However, it should not be understood that the descriptionsand figures constituting the parts of the disclosure limit the presentinvention. Based on the disclosure, a person skilled in the art maythink of examples of various modifications, transformations,alterations, operational technique, and the like.

For example, in the above embodiments, a system is described in whichEvolved UTRA and UTRAN (a.k.a. Long term Evolution or Super 3G) isapplied. However, a mobile station (user equipment (UE) terminal), abase station apparatus, a mobile communication system, and communicationcontrol method according to an embodiment of the present invention mayalso be applied to any other system capable of communicating using theshared channel.

Obviously, the present invention includes various embodiments notdescribed herein. Therefore, the technical scope of the presentinvention is defined only by the invention specifying matters accordingto adequate scopes of the claims based on the descriptions.

For explanatory purpose, plural embodiments are separately described.However, such separation of the embodiments is not essential to thepresent invention, and two or more embodiments may be used on an asneeded basis. Further, for explanatory purpose, specific values are usedto promote understanding the present invention. However, unlessotherwise described, the values are for illustrative purpose only andany other suitable values may be used.

The present invention is described above by referring to specificembodiments. However, a person skilled in the art may understand thatthe above embodiments are described for illustrative purposes and maythink of examples of various modifications, transformations,alterations, changes, and the like. For illustrative purposes, theapparatus according to an embodiment of the present invention isdescribed with reference to the functional block diagram. However, suchan apparatus may be provided by hardware, software, or a combinationthereof. The present invention is not limited to the embodimentdescribed above, and various modifications, transformations, alteration,exchanges, and the like may be made without departing from the scope andspirit from the present invention.

The present international application claims priority from JapanesePatent Applications No. 2007-052111 filed on Mar. 1, 2007, No.2007-161940 filed on Jun. 19, 2007, and 2007-329028 filed on Dec. 20,2007, the entire contents of which are hereby incorporated herein byreference.

1. A base station apparatus capable of communicating with a userequipment terminal using an uplink shared channel, comprising: a radioresource allocation unit configured to decrease frequency resourcesallocated to the shared channel, when transmission power of the userequipment terminal is less than a predetermined threshold.
 2. The basestation apparatus as claimed in claim 1, wherein: information about thetransmission power is UE Power Headroom reported from the user equipmentterminal.
 3. A base station apparatus capable of communicating with auser equipment terminal using an uplink shared channel, comprising: astorage unit configured to store a correspondence between a radioresource available for the shared channel, uplink radio qualityinformation, and a transmission scheme used for transmitting the sharedchannel; a determination unit configured to determine the transmissionscheme to be used for transmitting the shared channel based on theuplink radio quality information and the radio resource available forthe shared channel with reference to the storage unit; and anotification unit configured to notify the user equipment terminal ofthe determined transmission scheme.
 4. The base station apparatus asclaimed in claim 3, wherein: the storage unit stores, as thetransmission scheme, a data size used for the shared channel, and thedata size is determined to be a maximum value which satisfies apredetermined error rate, when the uplink radio quality information andthe frequency resource available for the shared channel are fixed. 5.The base station apparatus as claimed in claim 3, wherein: the storageunit stores, as the transmission scheme, a data size used fortransmitting the shared channel, a modulation scheme used fortransmitting the shared channel, and the amount of frequency resourcesused for transmitting the shared channel.
 6. The base station apparatusas claimed in claim 3, wherein: the uplink radio quality information isdetermined based on both SIR of a sounding reference signal and a poweroffset between the sounding reference signal and the shared channel. 7.The base station apparatus as claimed in claim 3, wherein: the poweroffset is determined based on path loss between the user equipmentterminal and the base station apparatus.
 8. The base station apparatusas claimed in claim 3, wherein: the radio quality information isadjusted based on a priority level determined by a data type.
 9. Thebase station apparatus as claimed in claim 3, wherein: the radio qualityinformation is adjusted based on both a decoding result of the uplinkshared channel and a required uplink quality.
 10. The base stationapparatus as claimed in claim 9, wherein: the radio quality informationis adjusted based on both the decoding result of the uplink sharedchannel and the required uplink quality with respect to one of plurallogical channel groups.
 11. The base station apparatus as claimed inclaim 10, wherein: the logical channel group used for adjusting theradio quality information comprises a logical channel group with ahighest frequency of transmission occurrences.
 12. A base stationapparatus capable of communicating with a user equipment terminal usingan uplink shared channel, comprising: a calculation unit configured tocalculate path loss between the user equipment terminal and the basestation apparatus; an MCS selection unit configured to select an MCSlevel of the shared channel based on the path loss; a determination unitconfigured to determine a transmission scheme to be used fortransmitting the shared channel based on the MCS level and a radioresource available for the shared channel; and a notification unitconfigured to notify the user equipment terminal of the determinedtransmission scheme.
 13. The base station apparatus as claimed in claim10, wherein: the transmission scheme comprises at least one of a datasize used for transmitting the shared channel; a modulation scheme usedfor transmitting the shared channel; the amount of frequency resourcesused for transmitting the shared channel; and HARQ information for theshared channel.
 14. The base station apparatus as claimed in claim 12,wherein: the MCS selection unit selects the MCS level of the sharedchannel based on the path loss, radio quality of a sounding referencesignal, and target radio quality of the sounding reference signal. 15.The base station apparatus as claimed in claim 3, wherein: thedetermination unit decreases the amount of frequency resources which isdetermined as the transmission scheme, when either the amount of data ina buffer of the user equipment terminal or the maximum amount of datawhich can be transmitted by the user equipment terminal is below a datasize which is determined as the transmission scheme.
 16. The basestation apparatus as claimed in claim 12, wherein: the determinationunit decreases the amount of frequency resources which is determined asthe transmission scheme, when either the amount of data in a buffer ofthe user equipment terminal or the maximum amount of data which can betransmitted by the user equipment terminal is below a data size which isdetermined as the transmission scheme.
 17. A communication controlmethod in a base station apparatus capable of communicating with a userequipment terminal using an uplink shared channel, comprising the stepsof: calculating path loss between the user equipment terminal and thebase station apparatus; selecting an MCS level of the shared channelbased on the path loss, radio quality of a sounding reference signal,and target radio quality of the sounding reference signal; determining atransmission scheme to be used for transmitting the shared channel basedon the MCS level and a radio resource available for the shared channel;and notifying the user equipment terminal of the determined transmissionscheme.